Through the field investigation and measurement,groundwater observation,irrigationtesting and the physical and chemical analysis of water and soil samples.this paper has prelimilarilydiscussed the sliding basic factors,distribution features,scale and harm of the landslides at the edgeof terrace,the formation mechanism of landslide is established as well.According to statistics,thereare 44 landslide in this region. From 1886 up to now,more than 20 Landslides have happened,thesliding ares of landslides varies from 0.2 to 2.5Km￣2,Since 1989,the direct economic loss caused byIandslide reached nearly 6 000 000 yuan by the average of 1 200 000 yuan per year.By the field ob-servation and indoor analysis,we think that the landslide in this region is generated by the ground-water from infiltration of irrigation water,the ground water expose in spring flow at the down partof slope。or bottom of pebble layer and the bottoln of old landslide。the mudstone at the bottom ofpebble layer is soften to mud by water,while it is comperessed and influenced,the sliding beIt willbe formed.The special stratum and high-steep slope landforms are all the essential factors for in-ducing of landslides.