The quake, which was logged as magnitude 5.9 by the US Geological Survey, struck in Gansu near the border with Qinghai, where Haidong is located.
That epicentre is about 100km southwest of Gansu province's capital, Lanzhou. Several smaller aftershocks followed the initial earthquake.
Xinhua reported the quake - which was felt in Xi'an in northern Shaanxi province, about 570km away - as magnitude 6.2.