The benchmark Shanghai Composite Index lost 2.12 percent, or 67.98 points, to 3,142.38.
The Shenzhen Composite Index, which tracks stocks on China’s second exchange, fell 1.23 percent, or 18.56 points, to 1,493.83.
China’s official Purchasing Managers’ Index (PMI) came in at 49.8 in January, its first contraction in more than two years, the government said over the weekend.
Investors were also cautious after the market regulator said Friday it had approved 24 initial public offerings (IPOs), which could divert funds from existing shares. (AFP)