China and Japan have been engaged in a long-time tug of war in the swimming pool.

Now, with the Doha Asian Games underway from December 1 to 15, the two bitter rivals are set to heat up their competition in the gold-rich event.

Japan has leapfrogged China at the Athens Olympics and World Championships with more golds and other medals in recent years.

Four years ago, China crushed Japan 20-11 in the gold medal count in Busan when Chinese women consolidated their dominance in Asia by taking 13 golds in the 16 events while Japan claimed victories in eight men's and three women's events.

This time, China will send a 39-member mixed team of veterans and new faces, including defending champions Qi Hui, Zhou Yafei, Xu Yanwei, Wu Peng and a group of teenagers.

It is believed that China still need to mostly rely on female swimmers to beat Japan.

Although Olympic 100m breakstroke champion Luo Xuejuan pulled out, China still have the upper hand in most of the 19 women's events, except in the backstroke and 200m butterfly. In these competitions, Japan has a star-studded line-up with Olympic bronze medallist Reiko Nakamura and two of world top butterflyers, Yuko Nakanishi and Yurie Yano.

In the men's competitions, Japan are set to make up for their loss in the women's pool.

Japan left Athens with three golds, one silver and four bronzes from swimming events their best performance for nearly 70 years.

Kosuke Kitajima became the first Japanese swimmer ever to win two individual golds, and he has been given the honour of captaining the Japanese delegation to the Doha Games.

But Japan will be without some other top stars, including Ai Shibata, the 800m women's freestyle gold medallist, as well as Sachiko Yamada, Tomomi Morita and Hanae Ito, who will be focusing instead on the world championships in Melbourne in March next year.

Zhang Yadong, head coach of the Chinese swimming team, refused to predict the number of gold medals the team would win but insisted: "The Asian Games are considered the mid-term exam for us, with the final exam being the Olympics. What we hope is that all swimmers could perform their best and the rookies will make auspicious debuts in Doha."

"We don't think winning the No 1 spot in the Asiad means that we are better than Japan. The most important battle is yet to come in the Beijing Olympic Games," the head coach said.

"Our biggest opponent is still Japan. But Part Tae-hwan from South Korea is also going to challenge us in the 200m, 400m and 1,500m freestyle."

Park won freestyle golds in the 400m and 1,500m at the PanPacific championships in Canada in August.

The 17-year-old also took five titles in the October national championships.

Diving dominance

In the diving pool, China have never let one gold slip from their hands in Asian Games' history and are determined to maintain their record with a squad made of both stars and rookies led by Olympic champions Guo Jingjing, Wu Minxia and Li Ting.

Former men's leader Tian Liang has been dropped from the national team. Olympic champions Hu Jia. Yang Jinghui and Peng Bo withdrew due to injuries.

Despite the series of withdrawals, titles in all events are still up for grabs among the all-Chinese squad, which includes nine world champions.

A number of inexperienced teenagers from the 12-member team have showed potential in previous competitions and are aiming to challenge veterans in a bid to have a shot at the 2008 Beijing Olympics.

"Some of the players are competing at the Asian Games for the first time. I believe they have the ability to stand on the podium. I hope the Asian Games will further polish their mental and physical capabilities," said Zhou Jihong, vice director of the China Swimming Administrative Centre.

According to Zhou, the main rivals are Japan, South Korea and the DPRK.

Ken Terauchi was the 3m springboard champion in the 2001 East Asia Games and finished eighth at the Athens Olympics.

Another Japanese duo Mai Nakagawa and Misako Yamashita were the bronze winners in the women's 10m synchronized platform at the 2004 World Cup.

South Korean pair Kwon Kyung-min and Cho Kwan-hoon are also podium contenders in the women's 10m synchronized platform after winning third place in the 2006 World Cup.