The site, set in a bamboo forest in China's southwest and financed by a Hong Kong animal charity, is part of efforts to stop "bear farming," which involves surgically implanting tubes to drain bile from the gallbladders of captive animals.
China encouraged the practice in the 1990s as a way to stop hunting of endangered bears. But injuries and illness suffered by caged bears led to criticism from environmentalists, who say demand for their bile can be met with herbal and synthetic alternatives.
"We will achieve the final objective of terminating bear farming in China," Chen Rensheng, secretary general of the official China Wildlife Conservation Association, said at a ceremony to open the sanctuary.
The $3 million center set up by the Hong Kong-based Animals Asia Foundation includes a hospital for injured bears and a 27-acre tract of bamboo forest.
The sanctuary near the city of Chengdu, capital of Sichuan province, is big enough for 100 bears. The foundation said it will be expanding under an agreement with Beijing to return 500 animals to the wild.
Bear bile, a bitter, greenish fluid that helps with digestion, has been used for centuries by Chinese physicians to treat diseases of the eye, liver and other organs.
China lists the Asiatic black bear as an endangered animal, according to the foundation. It said bile farming began in North Korea in the early 1980s as an export industry for the impoverished communist nation and spread to China, Vietnam and South Korea.
On Monday, the first bears released into the sanctuary stood at the open gate of their fenced-in living area, seemingly unfamiliar with the outdoors after months and sometimes years of captivity.
Most stayed close to the 15-by-50-foot pen and darted back inside whenever they heard a noise.
Two bears crossed a small clearing to snatch apples left on tree branches by the sanctuary staff in hopes of luring the animals out of their pen. The others went back inside after a short time outdoors, but the staff said they were likely to emerge once the crowd had left.
Sixty-four other bears seized from farmers are still being treated at the hospital for injuries, said Jill Robinson, the British founder of the activist Animals Asia Foundation.
One bear still in treatment was missing a paw, which a veterinarian said probably was lost in a trap.
The sanctuary said it received 17 newly seized bears this week and had to euthanize three of them because they had painful, untreatable tumors due to their treatment by bile farmers.
Animal rights activists have released photographs showing bears held by bile farmers in cages too small for them to turn around.
Chen, the environmental official, disputed activists' reports that Chinese bile farmers are holding as many as 9,000 bears. He said officials are conducting a survey to find the true number, but wouldn't say what officials think it is.
According to the foundation, China's estimated output of 15,500 pounds of dried bile per year is nearly twice its consumption level, suggesting farmers are supplying a thriving export trade.
Chen said he didn't know of any government approvals for exports and he didn't know whether the excess could be going.
"There are many imperfections in our current work," he said. "But you must admit that we are heading in the right direction."