The fighting was some of the worst unrest in China for decades
China says four more people have been sentenced to death over last year's ethnic unrest in Xinjiang province.
At least 25 people are now thought to have received death sentences over the violence - nine of the executions have already been carried out.
Nearly 200 people were killed in July during fighting between ethnic Uighurs and members of China's Han majority in the regional capital, Urumqi.
The violence was some of the worst ethnic unrest in China for decades.
The latest sentences were handed down at a court in the provincial capital on Monday, state media reported.
Xinhua did not say which ethnic group those sentenced belonged to, but their names indicated they were members of the Uighur population.
Eight other people were sentenced to life and one person was given a death sentence with a two-year reprieve, a court spokesman told the AFP news agency.
A death sentence with reprieve is usually commuted to life in prison in China, say reports.
Fighting broke out in Urumqi in July 2009, when a crowd of Uighurs - a Muslim minority which has long complained of repression under Chinese rule - attacked members of China's Han ethnic majority.
Shops were smashed and vehicles set alight, with passers-by being set upon by Uighur rioters.
Two days later, groups of Han went looking for revenge as police struggled to restore order.
Officials say most of those killed in the unrest were Han, and Urumqi's Han population demanded swift justice.
All those convicted over the unrest have been found guilty of crimes such as murder, damage to property, arson and robbery.
The violence came amid an increase in tensions between the Uighurs and Han in recent years.
Many Uighurs want more autonomy and rights for their culture and religion - Islam - than is allowed by Beijing's strict rule.
Millions of Han have moved to the region in recent decades, and while the majority of residents used to be Muslim Uighurs, Han now outnumber them in some areas, including Urumqi.