The number of Chinese private enterprises quadrupled in the past decade amid efforts to optimize the business environment, the country's top economic planner said Tuesday.

China's private enterprises increased from 10.85 million in 2012 to 44.57 million last year, Su Wei, deputy secretary general of the National Development and Reform Commission, told a press conference.

Su attributed the expansion of private enterprises to the improved business environment for the non-public sector, as the country has vigorously spurred the development of various economic entities over the decade.

China has long attached great importance to the private economy, encouraging it to play a bigger role in stabilizing growth and employment, and promoting structural adjustment and innovation.

The private sector contributes more than 50 percent of the tax revenue, more than 60 percent of the GDP, and over 70 percent of the technological innovations; it also provides more than 80 percent of the urban employment and accounts for more than 90 percent of market entities in China.

Highlighting the cultivation of high-quality market entities as one of the future reform goals, Su said China will step up the structural reform of private enterprises, support and guide the well-regulated and healthy development of capital, and foster a batch of world-class enterprises.