The effects of different rainfall intensity on spatial and temporal variation characteristics of soil moisture of different forest types were studied based on positioning and long term observation and data processing. Soil moisture of the Quercus variabilis forest land and the Pinus tabulaeformis forest land in Beijing region was monitored by the ECH2O monitoring system and the EM50 data acquisition system. The results showed that: (1) The daily soil water storage amount changed significantly with the precipitation. However, the average monthly soil water storage increased with the increasing amount of rainfall. (2) Vertically, the increase rate of soil water storage in the 0-40 cm soil layer of the Q. variabilis and P. tabulaeformis forest land decreased with the increase of the rainfall intensity, and the average increase rate of soil water storage of the Q. variabilis forest land (94.17%) was higher than that of the P. tabulaeformis forest land (84.19%), while the soil water storage rate in the 40-100 cm soil layer showed an increasing trend, and the average increase rate of soil water storage of the Pinus tabulaeformis forest land (15.81%) was greater than that of the Q. variabilis forest land (5.83%). (3) Soil water storage in the same layer was significantly different between the Q. variabilis and P. tabulaeformis forest land (p < 0.05), and it was also significantly different between different soil layers in the same forest land (p < 0.05). In terms of the spatial and temporal characteristics of soil moisture change in the Q. variabilis and P. tabulaeformi forest land, soil water storage distributions of the two forest types were different. Therefore, it worths considering mixing the two species together in afforestation. The results of this study could provide a reference and theoretical basis for the construction and management of vegetation in the mountainous areas of Beijing.