In this paper, a single-crystal silicon capacitive accelerometer is put forward. The accelerometer is composed of a single-crystal silicon vibration head and two backplates, forming a sandwich structure. With damping holes fabricated on backplates, the squeeze-film damping effect is reduced and a Q factor around 0.7 is obtained. This accelerometer has a simple fabricating process including wet and dry etching and ambient pressure packaging. Its tested sensitivity is 22.6pF/g and calculated noise level is lower than 100ng/√Hz, thus meets the demand of seismic applications.