The port of Shanghai seized seven snakes in a parcel sent from Taiwan, the city's inspection and quarantine bureau said on Tuesday.
It was the first time snakes have been seized in the mail, said the bureau.
The snakes, boa constrictors, are from central and south America. They are non-venomous, pet snakes, said Li Qiang, director of the bureau.
"The box was seized on Monday," said Li. "Live animals without inspection and quarantine could be carrying viruses or pathogens and are potentially harmful."
Living animals are not allowed to enter China through mails.