Hu Jia is being tried at the Beijing No. 1 People's Intermediate Court, a court official said. Canadian and Australian diplomats who tried to enter the court to observe the trial were turned away. Two local lawyers and friends of Hu's also were denied entry after being told the case was "sensitive."
One of Hu's lawyers, Li Fangping, said on his way into court that his client was healthy and in good spirits. He said he expected Hu would receive a five-year sentence on the charge of inciting subversion of state power.
"We think the explanation for this accusation is very unclear. If you apply it to any normal citizen, it can be a way of controlling freedom of expression," Li said.
Hu's case has gained international attention, with U.S. and European officials repeatedly raising it in meetings with Chinese officials.
Premier Wen Jiabao sidestepped a question about the activist at his annual news conference Tuesday. Wen avoided mentioning Hu by name and denied that China was rounding up political critics ahead of the Beijing Olympic Games in August.