Manufacturing grew in June at its strongest pace this year, but the expansion was weaker than normal.
Chinese leaders are trying to guide the economy toward self-sustaining growth based on domestic consumption, rather than exports and investment. Those plans have been complicated by weakness in exports, which support millions of jobs.
The premier and other leaders have ruled out an across-the-board stimulus but have tried to head off politically volatile job losses with more spending on building railways and other public works.
The ruling Communist Party's official growth target this year is 7.5 percent, but leaders have tried to downplay expectations, saying the expansion might come in under that level.
Economic growth also is under pressure from declines in housing sales and prices, which are dragging on construction and other industries.
"The Chinese economy is also facing downward pressure, but we will keep up our composure and not adopt strong stimulus," Li said. "Instead, we will increase the strength of targeted measures."
Li promised more market-opening reforms. He has said previously improvement in economic growth must come from structural reforms, rather than stimulus spending.
On Monday, he promised to reduce burdens on small companies and to give them more access to financing.
"We must also inspire the vitality of the market and lend support to the real economy," Li said.