With the repeated disturbance by tree cutting,grazing and fire for producing,the vegetation on Karst mountain area is destroyed greatly.Soil erosion becomes more and more serious in the recent years so that the ecological environment is being weaker and weaker.According to the investigation,the mean soil erosion has modules in Wujiang River Valley is about 500～1 500 t/(km2·a),and it is more than 5 000 t/(km2·a) in the upper reach area.About 4 mm topsoil is eroded each year in Wujiang valley.Serious soil erosion resulted in landification,the site habit has become more astringent and the area of difficult sites for tree planting increases more quickly.Some restrict factors for tree plantation in this area are as follows:high ratio of bare rock,uncontinuous soil distribution,shallow soil depth,great potential soil erosion dangerousness,weak ecological environment,small environment capacity and low threshold value to antidisturbance from outside.The vegetation rehabilitation in the degradation Karst area has become one of the most difficult problems in the world.In order to improve the ecological environment of Karst mountain areas,the most important measure is to rehabilitate forest vegetation.On the basis of analyses on the ecological characteristics and vegetation degradation reasons,some suitable tree species for plantation on Karst mountain area are selected and some valuable technique measures for forest rehabilitation and protection are given in the paper.It will provide a technical support and scientific basis for the ecological environment reconstruction in the great development strategy of the western part of China.