Numerous studies show that Karst area is more sensitive to influence of climate change and human activities, compared to the area in non-vulnerable condition. Therefore, quantitative simulating the land cover scenarios is important to understand the driving mechanism underlying land cover change in Karst area, and what policy should be carried out to prevent and reduce the land degradation. Especially, Karst area, as the typical ecological fragile zone, has been undertaking a series of ecological degradation, which have seriously affected the local socio-economic sustainable development. Karst area of Southwest China is one of the largest continuous Karst zone in the world, which major involves the Guizhou, Guangxi, Yunnan, Sichuan, and Chongqing province of China. This paper aims to develop a method for simulating the scenarios of land cover in Karst area and analyze its spatial distribution change under the global climate change. A simulation method of land cover scenario was developed on the basis of analyzing the correlation of spatial distribution between HLZ (Holdridge life zone) and the land cover, and the policy of basic farmland protection. According to the climate scenarios data of RCP26, RCP45, and RCP85 released by CMIP5 (the Fifth phase of the Coupled Model Intercomparison Project) and the land cover data in 2010 obtained from remoting sense images. Three land cover scenarios in Southwest China are respectively simulated in the next 90 years. The results show that three scenarios of land cover change have similar spatial landscape pattern and conversion trends. A gradual decrease was found in the following types of land cover, deciduous coniferous forest, deciduous broadleaf forest, grassland, cropland, ice and snow, and desert and bare rock; The other types of land cover would experience a moderate increase, namely, evergreen coniferous forest, evergreen broadleaf forests, mixed forest, scrublands, wetlands, construction land, water bodies and so on. Among the land cover types mentioned above, wetlands were projected to increase with the fastest rate (an increase of 5.28% per decade on average) and construction land were projected to increase most slowly (an average increase of 0.16% per decade), while desert and bare rock were forecasted to decline with the fastest rate (a decrease of 2.34% per decade on average) and cropland were forecasted to decrease most slowly (an average decrease of 0.26% per decade). It is worth noting that differences between land cover scenarios of 3 different climate scenarios lay in two aspects. On one hand, land cover scenario of every land cover type under RCP85 scenario stayed in top position in terms of the decadal change rate, especially, ice and snow decreasing far more than the other two scenarios. The next one was RCP45 scenario, land cover scenario of every land cover type under RCP26 scenario rank the last in terms of per decade change rate. On the other hand, each land cover type keep the same change trend under RCP85 and RCP45 scenarios during the following 90 years, while land cover scenario simulated with RCP26 data turn out to change in the opposite trend after 2070. Furthermore, the simulated result identify the method of land cover scenarios can avoid the difficulties which come from the complexity and uncertainty of mechanism analysis in land cover modeling, and suitable to simulate the land cover change on a regional scale.