The karst area of Southwest China is suffering from serious ecological and environmental problems due to soil erosion, while the research on soil erosion is not sufficient. Primary achievement had been systematically reviewed in this paper in three aspects: erosion characteristics, current researches about erosion on different spatial scales, key scientific problems. Based on the review, the authors figured out the shortcomings of the existing studies and pointed out the directions on erosion study in southwest karst region. The results showed that: (1) Due to the existence of a dual structure in karst environment including ground and underground erosion, the process of runoff and sediment production on slope scale and confluence and sediment transportation processes on catchment scale were more complex under the unique geological and hydrological backgrounds; (2) At present, most researches about erosion mechanism in karst area focused on slope scale and some achievement on quantitative evaluation of erosion factors was made. While continuous data with high quality about relationship between water and sediment on catchment scale was limited. When data was scarce, river sediment data could be used as an effective way to study soil erosion intensity and spatial and temporal variation in karst area; (3) It is more reasonable to use 50 t/(km2·a) as the grading standard of soil loss tolerance than the previous grading standard of soil erosion intensity. Given the complex relationship between rocky desertification and soil erosion, more quantitative studies about the effects of rocky desertification on soil erosion were still necessary. There were different viewpoints on soil leakage definitions, the leakage mechanism and soil leakage ratios, and new breakthroughs could be achieved by combining different methods and matching multi-scales. In conclusion, in order to further reveal the soil erosion laws and establish and revise available regional soil erosion forecasting models for Southwest karst areas, synchronous test and monitoring on slope, watershed, and channel spatial scales were urgently needed. The results could provide theoretical and technical support for promoting soil and water conservation works for the karst area of Southwest China.