In an unprecedented pre-Olympic move, China today announced that it was dropping 40 athletes and coaches from its Olympic Games roster shortly after members of its rowing team turned in blood samples with high EPO levels and some of its women's running team failed doping tests, officials said.

China--which has a long and troubled history of using hormones, drugs, herbs and other questionable tactics to improve the quality of its Olympic performance--was immediately praised for its swift action by Olympic officials.

"I'm very pleased," International Olympic Committee President Juan Antonio Samaranch said. "This is very good news. It shows the new system for detecting doping substances will work very well. . . . The objective is to have clean Games."

Australian Olympic Committee President John Coates said seven rowers, 14 track and field athletes, four swimmers and two canoeists apparently were withdrawn.

Also yanked was China's most famous coach, Ma Junren, who is known throughout the Asian nation for his "army" of female runners and their controversial victories and world records. The first sign that something was amiss with China's team came Tuesday when China's media reported that Ma suddenly had disappeared with his team of runners from their training camp high on a Tibetan plateau six days ahead of schedule. The Beijing Youth Daily said that drug inspectors had visited the camp four times. A report tonight by the official New China News Agency said that six of Ma's runners had been scratched from China's list.

"There are multiple reasons for Ma and his runners' disqualification," said He Huixian, the spokeswoman for the Chinese Olympic Committee. "Some of them are dropped due to suspicious blood-test results."

Despite difficulties and reports of widespread corruption within Chinese sports circles, some Chinese officials are committed to cleaning up China's image as an "Asian East Germany." In recent years, Chinese swimmers have been caught with growth hormone at an airport in Australia, and Chinese doctors have reported that several female athletes in other sports are sterile because of drug use.

One reason for the change of heart is that Beijing is a semifinalist in the sweepstakes for the 2008 Olympic Games. Beijing lost the 2000 Olympics to Sydney in a highly politicized vote. China also is slowly moving away from the Communist model of using success at sports as a way to prove the superiority of the socialist system. Chinese sports journalists have been told not to raise expectations for China's success at the Sydney Games and reporting about China's chances has been subdued.

The Chinese Olympic Committee reportedly administered blood tests to many of its athletes. A Chinese sports official confirmed that among 17 athletes, "a certain number" showed high levels of erythropoietin (EPO) that surpassed the IOC blood index levels. EPO is a naturally occurring hormone produced in the kidneys. It stimulates the production of oxygen-rich red blood cells and has become popular among athletes in high-endurance sports such as cycling, swimming, long-distance running and cross-country skiing.

The official Southern Daily reported Tuesday that Ma's runners were suspected of high EPO levels. It said a Chinese Olympic official had been dispatched to Ma's secret training camp in Qinghai province this week and that shortly after his arrival, Ma suddenly left in three buses with his runners. The Olympic official had earlier told Chinese media that Ma's participation in the Games would be "difficult."

Ma, the newspaper said, appeared ready for the controversy. Before leaving for the plateau, he told reporters that high red blood cell counts were normal after people move swiftly from a low elevation to well over 10,000 feet.

The most colorful coach in China, Ma was bidding for gold in the 5,000 and 10,000 meters in Sydney with a team of farmers' daughters, called "the Ma Family Army." The contingent was hoping to replicate the astonishing sweep by Ma's runners in 1993 at the Stuttgart world championships in Germany.

His runners grabbed all three medals in the 5,000 meters and took gold and silver in the 10,000. A month later, they shattered three world records at the Chinese national championships, with Wang Junxia shaving an astonishing 42 seconds off the 10,000-meter world record and 16.5 seconds off the 3,000-meter mark.

Controversy erupted as Western athletes and coaches around the world questioned Ma's methods. Ma acknowledged that he was tough with his runners but emphatically denied widespread suspicions that they were pumped up with banned drugs. He said their success came from high-altitude running and Chinese herbal tonics using mountain herbs, snakes, turtles, fungus and black chicken.

Last year, Wang Junxia openly broke with Ma, charging that he had pilfered team winnings, including three Mercedes cars, and abused athletes.

Responding to the Chinese move, IOC Vice President Anita DeFrantz, a former U.S. Olympic rower and a vice president of the international rowing federation, said the cuts from the Chinese team sent the right message to athletes.

"This is a warning to all athletes who wish to come to the Games with drugs in their system--stay at home," she said.