By field geo-hazard survey,statistical analysis on the characteristics of loess collapses in the Beishan Mountain of Tianshui City is performed using historical and current experimental data.The analysis anddiscussion on the formation mechanisms of loess collapses in the study area have revealed the material basis,mechanical properties,natural and artificial conditions of loess collapses.Results show that the geo-hazard isdominated by small or middle type of loess collapses,The results indicate that the geo-hazard of loess landslide is concentrated on small or middle type,the height of slope is from 15mto 40mand the gradient slopevaries from 58°to 90°.However,the height of slope assigned to potential loess landslide focuses on the rangefrom 10mto 38m,correspondingly,the gradient slope is from 48°to 90°.The loess collapses in the BeishanMountain were caused by precipitation,springs,earthquakes and human activities.Accordingly,some measures can be suggested for controlling the loess collapses.Results from the study may provide guidance forcontrolling loess collapses in this region in future.