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Following the varieties among soil texture, vegetation and precipitation events, the soil hydrologic process in the Source Regions of the Yangtze River varies obviously. By selecting typical segments in the headwater of Yangtze River and utilizing related data about man-made simulating rainfall and natural rainfall, the study shows that the soil moisture appeared clear change process on the vertical sections in the different physiognomy units, different vegetation types and different degradation degrees. In the dept of 0 similar to 10cm and 10 similar to 25 cm, the soil moisture change process is most evident. The hydrology process is more complex because of the most violent restriction of all kinds of external factors. In addition, the status of soil underlying surfaces is an important factor that affects soil hydrology process. The study indicates that the change of the soil moisture process in the Source Regions of the Yangtze River is one of the important factors that result in plateau vegetation degeneration, soil desertification and leanness, this change is due to the influence of natural environment and human activities.