Soil moisture is an essential variable in hydrology and ecology in karst region. In order to reveal the change rules of soil moisture during rainfall event, we monitored and analyzed the relationship between rainfall and soil moisture contents at 20 cm, 40 cm, 80 cm and 100 cm depth below surface in the grassland, cropland and bare land in Guizhou Province. Soil moisture was monitored by the ECH2O monitoring system and the EM50 data collector. The rainfall amount was collected by HOBO automatic weather station, and its measurement accuracy was 0.2 mm. The results showed that:(1) Vegetation cover, initial soil moisture content and rainfall density showed great influence on rainfall replenishment and redistribution of soil moisture in the soil profile. (2) To a certain extent, soil moisture affected by rainfall replenishment was not uniform in soil profile, which showed an up-down-up trend with the increase of soil depth, and 100 cm layer had the biggest rainfall replenishment compared with other layers. (3) The period in which soil moisture affected by rainfall could be divided into 3 stages:lag stage, rise stage and decline stage; as vegetation cover increased and rainfall density enhanced, the lag stage ended early, and the rise stage and decline stage started early. (4) The hysteresis effect in the lag stage enhanced with the increasing soil depth but receded with the increasing vegetation coverage. These results could provide a reference and theoretical basis for rational utilization and allocation of water resources and soil and water conservation.