State broadcaster CCTV said at least 113 people were killed in northwestern Gansu province and 18 more in neighbouring Qinghai after a shallow tremor on Monday night damaged thousands of buildings.
The quake was China's deadliest since 2014, when more than 600 people were killed in southwestern Yunnan province.
China's western hinterland carries the scars of frequent seismic activity. A huge quake in Sichuan province in 2008 left more than 87,000 people dead or missing, including 5,335 schoolchildren.
"The treatment and rescue of the injured as well as emergency infrastructure repair are ongoing," CCTV said on Wednesday.
The US Geological Survey said Monday night's magnitude-5.9 quake struck at a shallow depth at 11:59 pm local time (1559 GMT) with an epicentre around 100 kilometres (60 miles) from Gansu's provincial capital, Lanzhou.
Dozens of smaller aftershocks followed and officials warned that tremors with a magnitude of more than 5.0 were possible in the next few days.
Fears are growing that survivors awaiting rescue could succumb to the bitter cold, with temperatures at the epicentre in Gansu's Jishishan county expected to dip as low as -17 degrees Celsius (1.4 Fahrenheit) on Wednesday.
AFP reporters saw residents in the remote town of Dahejia, near the quake's epicentre, huddling around small fires outdoors on Tuesday, afraid to return to badly damaged dwellings.
Thousands of firefighters and rescue personnel have been sent to the disaster zone and state media said 2,500 tents, 20,000 coats and 5,000 rollaway beds had been sent to Gansu.
