If you're impressing the best, you must be doing something right.

The Chinese swim team's successful showing at the London Olympics didn't escape the attention of Michael Phelps. Phelps grabbed four more gold medals - the 100m butterfly, 200 IM, 4x200 free relay and 4x100 medley relay - in London to bring his record haul to 18.

He's retired now that the Games are over but said he's relieved to see new stars popping up.

"That's one thing that I am very excited about in the next four years," Phelps said on Tuesday.

"It's being able to keep following the production of swimmers all over the world and to see how much faster they can go. To have a lot of new faces is going to be fun."

Phelps said China's Sun Yang is the best of the lot.

"I've been able to watch all the swims," he said. "One of the most impressive is the men's 1,500m free. "He's so talented. His stroke is perfect. His catch and kick, everything about his stroke is flawless," Phelps said. "I think (coach Dennis Cotterell) could still help him improve in the future. Watching that (1,500), he was absolutely incredible."

Phelps defended double individual medley winner Ye Shiwen against the doping rumors that have been circulating.

"It's kind of sad that people have a great swim and that's the first thing they say," Phelps said. "There are people who just jump to that conclusion sometimes, and it's not right."

Phelps remained shocked at her time in the last lap of the 400 IM, which was faster even than men's gold medalist Ryan Lochte.

"For the 400 IM, I am happy that I was able to out-swim everybody else in the last 100 meters (in 2008)," he said. "That's what we've been joking about."

He knows better than anyone how much work it took her to get there.

"It's cool to see someone swimming like that, because they actually work hard and they love the sport and they do have very high goals for themselves," he said. "And they are going out to realize that."

sunxiaochen@chinadaily.com.cn