[Objective] This study aimed to provide an important scientific support for ecological policies and compensation of karst region.[Method] A method of using spatial succession sequences instead of time was adopted in this study.[Result] Compared with the maxiumum stage of forest succession,the potential of soil carbon sequestration in plantation is great.Compared with the early successional ecosystem,plantation can rapidly increase soil organic carbon content in soil deeper from 10 cm to 50 cm.In the initial stage of succession,organic carbon accounted for 37.96 % in surface soil,32.73 %,and in middle succession stage,31.02 % in succession climax and 26.26 % in plantation forest.[Conclusion] A method of conversion of cropland to forest and artificial afforestation can increase the amount of organic carbon,especially the deep soil.