There were four skaters in the final and three of them hit the ice in the kind of crash that is typical of this high-speed sport. Li was out in front of the wreck and all she had to do was coast to the finish line to give China its fourth consecutive women's 500-meter Olympic title.
She finished nearly 6 seconds in front of silver medal winner Arianna Fontana of Italy. Fontana was awarded second place after Britain's Elise Christie was penalized for having touched off the crash. Fontana won the bronze medal in the event four years ago.
Seung-Hi Park of South Korea also was caught up in the carnage and slid into the wall, but she wound up with the bronze medal.
Marianne St-Gelais of Canada, who won the silver medal in Vancouver, was eliminated in the semifinal heat. The top qualifying time was turned in by Fan Lexin of China, but she fell during the semifinals and slammed into the wall.
China's Meng Wang, the two-time defending Olympic champion, was unable to compete because of an injury suffered last month.
In qualifying for the men's 5,000-meter relay, the Canadian team failed to make the final and will see its streak of four straight Olympic gold medals come to an end.
Francois Hamelin fell during the qualifying heat to cost the Canadians a spot in the final.
The United States was also involved in a collision in its heat, but the judges ruled the wreck was caused by a skater from South Korea so the Americans were given a spot in the final. They will be joined in the race for the gold medal on Feb. 21 by teams from Russia, China, Kazakhstan and the Netherlands.