China's TangYi (top) is congratulated by her teammates ZhaoJing, JiLiping and Lu Ying, after the team finished second in the women's 4x100m medley relay final at the World Championships in Shanghai, China, on Saturday. Gero Breloer / Associated Press

Boasting home pool advantage, the host finished up with five gold, two silver and seven bronze medals, its best performance since the 1994 worlds and is ready for a tougher challenge in London.

The Chinese swimming team, despite a triumphant FINA World championships campaign, still sees a gap between it and the sport's powerhouses, and is now preparing for a tough battle at the 2012 London Olympic Games.

Boasting home pool advantage in Shanghai, the host finished up with five gold, two silver and seven bronze medals in the Oriental Sports Center, delivering its best performance since the 1994 worlds.

The once gloomy men's side, received a great boost thanks to new 1,500m freestyle world record holder, Sun Yang.

However, Yao Zhengjie, China's head coach, shrugged off the home glory, stressing the team's red-hot form here would not guarantee success in London.

"I am happy about the team's overall performance here and we basically achieved our goal to surpass Rome (world champs in 2009). But we can't say the London candy is already in our pocket. It will be more challenging and we have to work even harder from now on," Yao said on Saturday.

"We won several events by narrow margins and some good luck. Some swimmers also did not show their best in the competition. It all suggests a tougher trial next year when we swim abroad in London," he said.

Yao's primary concern is now on the women's side, which claimed three gold medals in Shanghai.

As the reigning champion and world record holder in the 4200m freestyle and 4100m medley relays, the Chinese women failed to defend the titles, only netting bronze and silver respectively.

Meanwhile, China's "Butterfly Queen" Liu Zige finished third in her favorite event, the 200m fly, finishing more than four seconds behind her world record of 2 min, 1.81 sec.

According to Yao, the relays showed China lags behind the all-round dominant US team, while he attributed Liu's lackluster performance to an "exhausting training scheme".

However, 200m individual medley champion, 15-year-old Ye Shiwen, and Jiao Liuyang, who claimed the title in 200m butterfly, brought a smile to Yao's face.

Despite a perceived flawed women's performance, the rising of the men's team has inspired the coach to set high goals in London - with Sun as the spearhead.

Sun, 19, slashed 0.42 second off the 10-year-old 1,500m freestyle's record by clocking 14:34.14 to win his second title after already grabbing gold and silver medals in the 800m and 400m free respectively.

"Undoubtedly, Sun is overwhelming in the 1,500m, but he is still a rough youngster who needs to be more mature. The 400m's loss to archrival Park Tae-hwan should have been a lesson to him, but he still deserves high expectations next year," Yao said.

Apart from Sun, China's first male world champion swimmer, Zhang Lin, who set the 800m freestyle's world record two years ago, showed he was returning to form in the 4200m free relay, the only event he swam, after a year-long adjustment period.

The 24-year-old Beijing native will remain the team's spiritual leader, said Yao.

"I was worried about him before the event, but now I can say he is still on the top and returning to his best. He will be solid enough in London," Yao said.

Fully aware of China's improvement during its offshore training camp in Australia, the Aussies' head coach, Leigh Nugent, said the country was a formidable foe for the rest of the world.

"We all see their performances. Sun and some of the women swimmers already rule their events. The men's 4200m free relay bronze was also noteworthy. Definitely China will be a tough opponent in London for all the contenders," Nugent said.

Meanwhile, Yao warned the squad to keep an eye on the European countries, including France and the Great Britain, which performed well in Shanghai.

"They are coming up for more medals than usual. London will be their home pool and we will also face challenges from them, not only the traditionally strong Americans and Aussies," Yao said.