People returning to Beijing must avoid contact with others for 14 days. They have to be in quarantine for two weeks, according to the Beijing Daily state medium.
The authorities threaten to impose sanctions against people who return to the Chinese capital and who ignore this rule.
The measure is intended to help prevent the spread of the new coronavirus.
The virus appeared in Wuhan in December, around 1,000 kilometres south of Beijing.
More than 64,000 cases of infection have already been detected and nearly 1,400 patients have died from the consequences.