Soil moisture of forest ecosystems acts as a carrier of matter and energy cycle, affecting growth and development of vegetation, and affecting regional climate by changing the circulation and distribution of water between land and atmosphere. Based on the long-term observation data of 9 forest ecosystem sites in different climatic zones in China, this study explores the spatial pattern and temporal dynamics of soil moisture in Chinese typical forest ecosystems from 2005 to 2016, and further analyzes its influencing environmental factors. The main research conclusions are as follows: (1) the multi-year mean of soil moisture in 9 forest ecosystems ranges from 12.45% to 36.30%. The spatial distribution is that soil moisture in the temperate zone, subtropical zone and tropical zone is relatively high, while that in the warm temperate zone is relatively low. Precipitation minus evapotranspiration (P-ET) can explain 62% (P<0.05) of the spatial pattern of soil moisture of forest ecosystems in China. (2) Soil moisture shows an upward trend in north China and east monsoon area in China and the increase of precipitation is the main cause. Soil moisture of Beijing Forest Ecosystem(BJF), Dinghushan Forest Ecosystem(DHF), Heshan Forest Ecosystem(HSF) increases significantly by 0.67%/a, 1.72%/a and 0.70%/a, respectively. Soil moisture shows a downward trend in Southwest China which is caused by both the decrease of precipitation and the increase of ET. Soil moisture of Gonggashan Forest Ecosystem(GGF) and Ailaoshan Forest Ecosystem (ALF) shows a significant downward trend with the decreases of -1.77%/a and -0.94%/a. The correlation between the temporal trend of soil moisture and P-ET was the highest (R=0.59, P<0.01). (3) In the forest ecosystem where soil moisture is decreasing, the change of soil moisture in spring dominates the interannual trend, while in the forest ecosystems where soil moisture is increasing, the interannual trend is dominated by autumn and winter. The CERN soil moisture observation data reflects the feedback effect between soil-vegetation-climate under undisturbed natural forest conditions, which can also provide long-term verification data for model-based soil moisture research.