BEIJING—China’s growth remained at 7% in the second quarter, a level economists had thought would be hard to reach amid broad signs that Beijing’s policies to jump-start the world’s second-largest economy hadn’t yet taken hold.

Economists had expected that a large jump in brokerage fees from stock-market turmoil in the final weeks of June would give a bump to growth, but most had expected growth below 7%.

That it still hit that level—which is also the government’s growth target for the full year—could renew a debate about the reliability of Chinese statistics.

National Bureau of Statistics spokesman Sheng Laiyun said in a news conference after the release that improvements in the economy had been “hard won.”

“There are positive signs in the second quarter, with the overall economy stabilizing and staging signs of improvement,” he said. “We need to work hard to cement the situation.“

He said the data hadn’t been inflated and that they “objectively described the situation.”

The data come as the world searches for growth, and the number gives an endorsement to the economic groundwork Beijing has laid in recent months to put a floor under the country’s slowdown, with a series of measures to lift spending, offer tax breaks and cut interest rates.

Other statistics released Wednesday by the National Bureau of Statistics showed little sign of turnaround in a quarter that started against the backdrop of a broad stock rally and ended under the shadow of that rally’s collapse.

Value-added industrial production grew 6.3% year-over-year in the first half, down from the 6.4% growth in the first quarter, while growth in fixed-asset investment fell to 11.4% from 13.5%, and retail-sales gains slowed to 10.4% from 10.6%, the statistics bureau said.

The benchmark Shanghai Composite Index opened lower ahead of the report; it fell further after the data release and ended the day 3% lower.

The broader economy had appeared to veer little from its recent slowdown course, underlining both how divorced the stock market remains from economic fundamentals as well as the economy’s sluggish response to the government’s efforts to revive it.

The median forecast by 14 economists surveyed by The Wall Street Journal had been for 6.8% growth in the quarter.

“Over the second quarter, pretty much everything other than the financial sector slowed,” said Brian Jackson, an economist with data provider IHS Inc., on Tuesday, before the GDP release.

Economists have frequently questioned the methodology underpinning Chinese statistics, given discrepancies between regional and national growth figures, data collection shortfalls and, at times, a lack of transparency. Several economists have constructed alternate measures of growth based on freight rates, electricity output and other data. Citibank said recently that it believes China’s actual growth rate could be closer to 5%.

After the data release, Conference Board economist Andrew Polk said the 7% second-quarter growth figure raises questions about how the official data was assembled at a time when the broader economy faces multiple headwinds. “Clearly the headline number has become more divorced from at least the underlying numbers they’ve given us and at worst from reality,” Mr. Polk said.

In recent weeks, there had been some signs that the economy was starting to stabilize. Property prices in China’s largest cities are rising after an extended slump. Industrial production edged up recently. And new bank loans were up significantly in June, adding capital for companies’ expansion.

But global demand remains weak, and broad areas of the world’s second-largest economy had largely failed to respond to four interest-rate cuts and several adjustments in reserves that banks are required to hold since late last year.

“Across the board, things are weak,” Mr. Jackson said.

Infrastructure spending, a staple driver of Chinese growth, has failed to gain much traction as local governments battle debt and other constraints on their outlays.

In a bid to get projects going, the State Council—China’s cabinet—issued at least 10 guidance papers on infrastructure investment in May. China’s top economic planning agency, the National Development and Reform Commission, has outlined 1,043 projects for public-private partnership totaling 2 trillion yuan ($322.1 billion) in investment. But of those, only about 10% are under way, according to research firm Gavekal Dragonomics.

Local government spending accounted for 27% of China’s gross domestic product last year, according to Goldman Sachs, which estimates that a 1 trillion yuan shortfall in local infrastructure investment from 2014 could cut growth by 0.7 percentage point this year.

A continued economic slump had raised the pressure for more government stimulus. The People’s Bank of China, which has been enlisted to throw its weight behind an emergency rescue of the stock market, is sticking to an accommodative but cautious monetary-policy approach. In a statement Tuesday that mirrored word for word one last quarter, it pledged to maintain “prudent” policies and ensure “adequate” liquidity.

The 30% drop in Chinese share prices over three weeks isn’t expected to cause major damage to the broader economy given the relatively small number of Chinese stock investors. Similarly, the stock market’s upward march since late last year had little economic effect beyond boosting the financial sector itself, economists say.

Without that bump, however, growth would have been even lower. As trading picked up pace in the first quarter of 2015, the contribution from financial services to GDP expansion nearly doubled to 1.3 percentage points compared with 0.7 percentage point in 2014, according to research firm Capital Economics. Detailed data weren’t yet available on the second-quarter contribution from the financial sector.

Economists had expected the impact could be even higher in the second quarter given extensive, and at times panicked, trading in recent weeks. “If the relationship still holds, we expect quite a big contribution,” said Julian Evans-Pritchard of Capital Economics.

The Shanghai Composite Index has partially recovered in recent days. But the slump has raised concern that much-needed reform could be put on hold at a time when China is trying to direct its economy away from exports and manufacturing to consumer-led growth.

Despite the broader slowdown, consumption has held up reasonably well this year. That could change with a rise in unemployment as more factories close.

And for some consumers, the stock market’s gyrations have already put a damper on spending plans.

Ricky Hu, an employee at a state-owned company in Beijing, said he is watching his pennies more carefully after losing about 30% of his savings in the recent stock-market plunge, although he believes the market will recover eventually.

In addition, raises are getting smaller at his company, Mr. Hu said, and he’s increasingly nervous he will be laid off. “I’m worried about it all the time,” he said. “You can never tell when it will come.”

Premier Li Keqiang has browbeaten local officials in recent months to spend more, accusing them of laziness and saying that this year’s “about 7%” growth target remains achievable.

On Friday, at a meeting of economists and businessmen, Mr. Li said China needs to maintain a balance between growth and economic restructuring. “China’s economy still boasts remarkable tenacity, potential and flexibility,” Mr. Li said, according to the official Xinhua News Agency.

Others are less sanguine. “It seems like the economy will decelerate for the foreseeable future,” said Moody’s Analytics Ltd. economist Alaistair Chan.

“I guess the government can keep gradually moving down the goal posts by saying ’about’” with their targets, Mr. Chan added.