A total of 151 people, who had close contact with the dead man, are put in quarantine.
They are under medical observation.
None of them has reported syndromes of the disease so far, state-run Xinhua news agency reported.
The case was reported in Yumen City under the jurisdiction of Jiuquan City, the Jiuquan government said yesterday.
The man, who died on Wednesday, had been in contact with a dead marmot, which is of the squirrel family.
The National Health and Family Planning Commission has sent disease prevention and control specialists to Yumen to prevent the plague from spreading.