In order to better understand soil moisture of natural slope and related factors of Haikou in the context of climate change. Based on soil moisture data of natural slope and meteorological observation data from 2005 to 2011 in Qiongshan meteorological observation station at Haikou, the relationship between soil moisture of natural slope and meteorological factors were analyzed by statistical methods. Results were shown as follows: (1) the annual variation of soil moisture from 10 to 50 cm of natural slope had a positive trend, the seasonal variation be same to annual variation, but instability in winter and spring; (2) monthly variation of soil moisture from 10 to 50 cm had a wavy change, up wet and down dry during February to October and on the contrary during November to January; (3) as the depth of soil, the deeper moisture was more smaller, and the difference was more significant, especially in layer 40-50 cm. (4) soil moisture at 20 cm was closely related to the soil moisture, so used soil moisture at 20 cm to instead of soil moisture at 10-50 cm, and found that soil moisture had a negatively correlated with soil temperature, a positively correlated with precipitation, and the regression equations on soil moisture and meteorological factors on different seasons passed the T-test at a confidence level of 0.99.