The choppers carrying more than 20 people flew from Gyirong County in southwest China's Tibet Autonomous Region to Kathmandu, the Nepalese capital, this morning and returned in the afternoon.
The choppers helped in local transportation and rescue missions and it may continue for days, an official with the Chengdu Military Area Command, to which the three helicopters belong, was quoted as saying by state-run Xinhua news agency.
China's Ministry of Foreign Affairs said some 360 tonnes of relief material was due to be sent to Nepal.
China has sent seven medical and rescue teams to the quake-affected country.