Abstract: In order to study the soil respiration of major successional communities in Karst areas, LI-6400-09 portable soil respiration fitting equipment was employed in this study to carry on continuous observation on the soil respiration rates, of which were the two major successional communities of Karst primary forest and secondary forest as the research subjects. The results showed that:(1)The soil respiration rates, soil temperature and temperature inside forest were different in the diurnal changing range among the different successional communities and different months.(2)There were distinct seasonal changes for the soil respiration rates of the two major successional communities,and which were summer, autumn, spring and winter in decreasing order. The monthly mean of soil respiration rates ranged from 0.39-4.65 μmol/(m²·s)in Karst primary forest and ranged from 0.93-4.56 μmol/(m²·s)in secondary forest, respectively.(3)The soil respiration rates were significantly and positively correlated with soil temperature in different depth and temperature inside forest.(4)The Q₁₀ value of soil respiration ranged from 3.82 to 4.07 in Karst primary forest and ranged from 2.52 to 2.61 in secondary forest, respectively. Moreover, the Q₁₀ value in Karst primary forest was higher than in secondary forest; with soil depth increase, the Q₁₀ value increased.