It analysed that runoff,plants and soil in three different forestation modes and hillside cultivation in Karst area of the southeastern of Yunnan.The results showed that returning land for farming to forestry had remarkably impact on soil buildup,water retention increased fertility.We also could get good effects of conversation of soil and water by constructing pure forest,mixed forest,and complex management of commercial forest and herbage.Size these plants down by comprehensive consideration to water retention, soil retention and fertility retention was Alnus ferdinandi-coburgii:Trifolium pratense>Cupressus lusitanica>Zanthoxylum bungeanum:Lotus uliginosus. Alnus ferdinandi-coburgi iand Trifolium pratense mixed forest could decrease runoff flow and loss of run-off soil 37.23% and 99.40% respectively than those of hillside cultivation.The loss of soil solid nutrition was also decreased, which organic matter,total nitrogen,total phosphorus,total potassium,alkaline hydrolysis nitrogen,available phosphorus,and available potassium respectively decrease 99.37%,99.43%,98.68%,98.86%,99.34%,99.35% and 99.58%.The loss of nitrogen,phosphorus and potassium in fluid nutrition was respectively decreased 32.45%,19.80% and 21.57%.Soil nutrition was increased because of decreasing loss of runoff soil and soil nutrition,meanwhile organic matter had some impact on soil reform and nutrition supplement.While soil nutrition in hillside cultivation had some certain decreased.