Trading was on Thursday halted for the day on the Shanghai and Shenzhen stock markets after shares tumbled over seven percent as the circuit breaker mechanism was triggered.
Earlier, the smaller Shenzhen index opened 1.88 percent lower at 11,504.9 points, Xinhua news agency reported.
The ChiNext Index, tracking China's NASDAQ-style board of growth enterprises, lost 2.15 percent to open at 2,415.33 points.
