But the search for survivors went on in the stricken southwestern province of Sichuan as families refused to give up hope for their loved ones, and rescuers found two more people alive in the rubble.
Around the vast country of 1.3 billion people, air raid sirens and car, train and ship horns will sound to "wail in grief" at 2.28 p.m. (7.28 a.m. British time), the time the quake hit a week ago, the official Xinhua news agency said.
The national flag in Tiananmen Square in central Beijing flew at half mast after a ceremony at dawn.
"I have come today with a heavy heart," said Liu Xianzeng, watching the ceremony in Tiananmen Square. "I feel for the victims of the earthquake and soldiers who are helping there."
Public entertainment was halted and a three-minute silence was also to be observed to mark exactly a week since the quake, the government said.
The Shanghai and Shenzhen stock exchanges and the futures exchanges in Shanghai, Zhengzhou and Dalian would halt trading for three minutes from 2.28 p.m.
In Beichuan, one of the worst hit towns in Sichuan, relatives continued to travel back into the disaster zone to look for family members and see the damage for themselves.
"It's a good idea but maybe it's a bit early,' said Zhou Wanli of the national state of mourning, sitting in the back of a truck heading into Beichuan.
"All we can care about for the time being is finding our relatives. We don't want to memorialise them if we don't even know if they're alive or dead," he said.
SURVIVORS RESCUED
The official death toll from the 7.9 magnitude quake stands at nearly 32,500.
Some 220,000 people are reported injured and a further 9,500 are thought to be still buried under the rubble in Sichuan. Most are feared dead, but some are still being pulled out alive.
