Abstract: Soil conservation function is one of the important means of measuring the effectieness of ecological rehabilitation of rocky desertification in karst areas. Based on InVEST model, “3S” technology was used for interpreting rocky desertification in Guanling-Zhenfeng Huajiang Demonstration Area in 2005, 2010 and 2015, and the response mechanism between rocky desertification and soil conservation was studied. The results showed that, from 2005 to 2015, (1) Degree of rocky desertification in the Huajiang demonstration area presented an overall downward trend, and areas of rocky desertification was reducing from 3 773.56 to 3 474.23 hm². Moreover, the overall soil conservation quantities presented an upward trend, rising from 279 900 to 348 100 t. the increasing quantities of soil conservation per unit area, from 2005 to 2010, was concentrated in 6-30 t·hm^-2·a^-1, and in the last five years it slowed within 0-6 t·hm^-2·a^-1. (2) although differences in land-use type, slopes, and soil thickness, soil conservation functions did not show a simple decline at all, but rather: intensity > moderate, mild > potential, non-karst > no rock desertification. Among them, the difference between light and potential is biggest difference up to 5.53 t·hm^-2·a^-1, which indicated that potential rocky desertification is the harness priority in the future. (3) In 2005-2010, the increasing quantities of restoring-type soil conservation of rocky desertification was 10.27 t·hm^-2·a^-1, which was reduced to 3.01 t·hm^-2·a^-1 in 2010-2015 due to the change of land-use type and harness effectiveness. The change of the increasing quantities of stable type soil conservation of rocky desertification maintain the most stable; soil conservation function rises rapidly in intensity-rocky desertification slowdown areas, while mild-rocky desertification area is smoothest, which indicated that the harness period is long and needs to be gradual. Therefore, in the process of harness, it is necessary to consider the soil conservation function of different degree of rocky desertification and the effectiveness of its restoration.