The Xinhua news agency said that 76 people were sentenced on Wednesday and more than 950 were detained.
Xinhua also said in a report that the Lhasa Municipal Intermediate People's Court also gave suspended death sentences to two other people, and sentenced another to life imprisonment.
Suspended death sentences are usually changed to life imprisonment after two years.
|China has kept a tight grip on security in Tibet following last year's unrest [GALLO/GETTY]
Xinhua said the five were tried in three separate arson cases that left seven people dead and five shops completely destroyed.
One other arson case in which five people were killed is still being heard, it said.
Xinhua identified one of those sentenced to die as Losang Gyaltse, saying he had burned two clothing shops in downtown Lhasa on March 14, killing a shop owner.
A second man, Loyar, was sentenced to death for his role in the burning of a motorcycle shop that killed the owner, his wife, his son, and two employees, Xinhua said.
Xinhua quoted an unidentified court official as saying the trials had been open and fair according to Chinese law, and that the accused were defended by lawyers and provided with Tibetan interpreters.
However, this claim could not be independently verified.
A spokesman for the Dalai Lama's self-proclaimed Tibetan government-in-exile in India said those sentenced had not received a fair trial.
"These decisions are made by a kangaroo court of law. There is no proper legal defense for the accused," Thupten Samphel told the Associated Press.
"These kinds of decisions increase China's Tibet problem. China should show magnanimity to make Tibetan people less resentful."