The benchmark Shanghai index opened at 3,975.21, up 288.29 points, before paring its gains to 3 percent to trade at 3,797.34 as of 10 am.
The Shenzhen Component Index rallied 2.3 percent to 12,532.29.
Earlier in the morning, the Shanghai Composite Index surged as much as 7.8 percent at the open, as regulators launched a flurry of measures to stem market plunge.