The sentences are the first to be handed out since Buddhist monks took to the streets March 10 to mark the 49th anniversary of a failed uprising against Chinese rule, which erupted into widespread protests on March 14.
The sentences were read out in an open court in Lhasa, Xinhua reported. The trial was attended by around 200 people.
According to official reports, the riots left 19 people dead and 623 injured, while Tibetan exile groups put the figure much higher with at least 100 civilians killed.
According to contradicting reports from the official China and exiled free Tibet supporters, up to 2,000 people are currently being held in custody for their part in the protests.
Several Western leaders earlier said they could boycott China's Olympic opening ceremony over the country's brutal crackdown on the protests and refusal to negotiate with the Dalai Lama, Tibet's spiritual leader.
The Olympic torch, which is now in Vietnam, has been met by protestors in a number of cities including Athens, London, Paris, San Francisco and New Delhi. It is expected to arrive at the opening ceremony in Beijing on August 8.
