CHONGQING, Sept. 25 (Xinhua) -- Chen Yanyan and Shi Feng claimed their second gold medals respectively in individual events on Tuesday at the ongoing Chinese national swimming championships.

Chen, 22, won the women's 200 meters backstroke in 2 minutes 12.68 seconds to add to her gold in the women's 100m backstroke on Sunday.

Chen said that she was not satisfied with her result although it is above the Olympics A qualification standard.

"I need more time to train, and I hope I can make a breakthrough through training abroad," she said.

Shi, who stunned Chinese top butterfly swimmer Wu Peng to win the men's 100 meters butterfly, continued his impressive showing by winning the men's 50 meters butterfly final, a non-Olympics event.

Shi said he would also try to reach the Olympics A standard at the men's 200 meters butterfly race.

"After all, the Olympic Games is the premier competition," he said.

In women's 50m freestyle final, veteran Zhu Yingwen beat teammate Pang Jiaying to win in 25.42 seconds.

Xue Ruipeng took the men's 200m breaststroke final in 2 minutes16.06 seconds. National record holder Lai Zhongjian finished thirdin 2:17.15.

Jiao Liuyang, 16, won the women's 200m individual medley, while13-year-old Li Xuanxu, winner of the 400m individual medley at the championships, finished a distant eighth in the final.

The six-day national swimming championships, which starts on Staurday, served as an Olympic qualifier which saw more than 300 swimmers from 22 teams participating.

Chinese women swimmers posted Olympic qualifying results in every event except the 200m freestyle, while only eight Chinese men have met Olympic standards so far.