The authors made a survey of the disaster caused by heavy rainstorm occured on July 23, 1988(with a 300 year rainstorm frequency, precipitation in the center point was 210～240mm)in the hilly and gully regions in the east part of Gansu Province on the loess plateau. Based on the actual data, they analysed that this heavy rainstorm was formed by local geothermal convenction and initiated by the "人" -shaped shearing instability over 700 hpa. The heavy rainstorm only lasted from 2:05 to 2:35 in the morning, causing serious disaster. This paper analysed the natural and manmade causes of disasters caused by heavy rainstorm in the Yuan area. Also, it analysed the advantages and disadvantages of water and soil conservation engineering structures including stripe lands, gully head control works, reservoirs and dams as well as afforestation. Therefore, the idea of comprehensive control system of Yuan, slopes and gullies was presented, and it was suggested that the disaster resistant ability of water and soil conservation planning, design and construction should be improved since rainstorms characterized by heavey rainfall and great rain intensity are mostly caused by local geothermal convenction.