Flags are flying at half mast across the country and public entertainment curtailed as a mark of respect, one week after the quake hit.
The official death toll has now reached 2,039.
Tens of thousands of people have been left homeless by the earthquake but relief supplies are now pouring into worst hit area, the town of Jiegu.
Another 195 people are still missing after the 6.9-magnitude quake and 12,135 have been injured, state news agency Xinhua reported.
Rescue workers are continuing to dig through the rubble in and around Jiegu in Yushu County.
Hopes were raised by the rescue of three people on Monday who had survived nearly a week under the ruins of buildings.
A four-year-old girl and an elderly woman were rescued from a house near Jiegu and later in the day, a woman in her 30s was pulled alive from her home.
Schools open
Tens of thousands are now living in temporary shelters or tents in freezing overnight temperatures.
The officials have warned that temperatures in the Himalayan plateau region are expected to fall further.
"We estimate that in the next few days, the rain, snow and low temperatures will harm relief work," the National Meteorological Centre said.
It warned that those working in transport, medicine and health should "strengthen their guard".
Aid has been arriving in large amounts in the region, with convoys of trucks reportedly backed up for miles along the highway from the provincial capital, Xining.
Some schools have also reopened, although where school buildings have collapsed lessons have had to be held in tents.
Danzeng Jiangcuo, a maths teacher at Yushu No.3 Elementary School, said students were receiving psychological care as well as their usual lessons.
"We are trying to help them forget the disaster and not feel scared anymore," he told Xinhua.
Ninety-seven percent of Yushu's population is ethnic Tibetan, and there were reports that language difficulties were affecting relief work.
China's President Hu Jintao, who visited Jiegu at the weekend, has promised an all-out effort to rebuild the region.
'Hostile forces'
Tibetan Buddhist monks have been heavily involved in the emergency operation, digging through the rubble for survivors and distributing aid.
They have also been collecting bodies and holding funerals.
The Dalai Lama has appealed to the Chinese authorities to allow him to visit the quake zone.
The exiled Tibetan spiritual leader was born in Qinghai province but has not set foot in China since a failed Tibetan uprising more than 50 years ago.
Correspondents say it is highly unlikely that the Chinese government - who see the Dalai Lama as a dangerous separatist - will agree to his request.
At a government meeting on Monday, China's top parliamentary advisor, Jia Qinglin, warned of "hostile forces from abroad working to cause disruptions and sabotage" in the quake's aftermath, the Associated Press reports.
He did not specifically mention the Dalai Lama but he and his supporters are often referred to as "hostile forces" by the Communist government.
