Based on the data of man made soil and water loss(1986～1992) in Guangdong province,the authors studied the main factors of man made soil and water loss,and its economic loss,increasing rate and harm,then put forward the countermeasures of the prevention and control.The sequence of sum total index in all items is:capital constructionmining reclaiming wasteland with steepslopebrickkilndestroying forest and vegetation.The economic loss is 31.36×10⁴yuan/km² (RMB),an average increase of 414.06 km² and 2 926×10⁴ m³.The authors put forward that man made soil and water loss result from the irrational human actions, as long as execution of the soil and water conservation,supervision and necessary measures of rehabilitation and prevention are enforced, much man made soil and water loss would be refrained, prevented and controlled.