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.
Almost 1,000 were injured across the two provinces, according to state news agency Xinhua.
The quake was China's deadliest since 2014, when more than 600 people were killed in southwestern Yunnan province.
AFP reporters saw families sheltering in makeshift tents constructed from wooden poles and tarpaulins outside the local Majiahe mosque near the epicentre in Gansu's Jishishan county, with outdoor stoves and blankets salvaged from their homes their only sources of warmth.
Residents crowded around stoves in large tents set up by the local government on a basketball court in Liugou township.
One resident told AFP some tents had as many as 35 people huddling inside.
Children lay under blankets, playing on their phones, while adults attempted to prepare meals out of the limited supply of instant noodles provided by the authorities.
AFP saw rescue teams unloading large bundles of supplies, including more tents.
Nearly a thousand people who were injured have been sent to hospitals, with 87,000 people moved to "temporary shelters" in Gansu alone, CCTV said.
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.
"Search and rescue work basically ended by 3 pm yesterday and the main work now is to treat the injured and resettle the affected population," an unidentified official from Gansu's Emergency Management Department told a news conference 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 its 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 could succumb to the bitter cold, with temperatures in Jishishan expected to dip as low as -17 degrees Celsius (1.4 Fahrenheit) on Wednesday.
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.
