BEIJING - China could hardly repeat the glory of winning the most gold medals when it competes at the London Olympic Games this summer, a top sports official has said.

Speaking to Xinhua as the London Olympics marked the 100-day countdown on Wednesday, Cai Zhenhua, deputy minister of China's State General Administration of Sports, played down the country's medal prospects in the British capital.

"Based on a study about the past five Games, the host country win record high medals at their home Olympics, but their medals total would drop dramatically at the next edition," Cai said.

"We will face strong challenges in London. It won't be an easy job," he added.

China topped the Beijing Olympics gold medal tally with 51 gold, 21 silver and 28 bronze, compared to the United States with 36 gold, 38 silver and 36 bronze.

Cai, who was formerly a table tennis player and coach, noted that the scenario of world sports has changed in the post-Beijing Olympics era.

"The United States has maintained its overall strength, and countries like Russia and Britain have increased their input in sports, while China is less competitive in some sports," said Cai.

"As a number of Olympic and world champions retired after the Beijing Games, a younger generation would form the bulk of Chinese Olympic legion. Some of our young athletes lack international exposure and consistency, so we cannot be very optimistic about their performances.

"Furthermore, London is not Beijing, we are no longer competing on home soil. We have to overcome the time difference, unfamiliar weather as well as logistics inconvenience. So our target for 2012 is just to remain in the lead pack on the gold medal table," he added.

So far, China has secured over 310 Olympic spots in 172 events. And with Olympic qualification competitions still in action for triathlon, boxing, wrestling, tennis, Chinese athletes are set to grab more quotas.

"We expect to send a team of 380-strong athletes to London. And the delegation will be formed in early July," said Cai.