In order to know the soil infiltration characteristics of the Xilamuren grassland, a study was carried out in an enclosed grassland to investigate the soil infiltration process of six plant communities (Allium mongolicum, Convolvulus ammannii, Leymus chinensis, Koeleria asiatica, Stipa krylovii, and Stipa krylovii) using the double-ring sampling method, and the influencing factors were analyzed. The results indicated that soil infiltration rates in different plots could be divided into three stages. The first stage was from 0 to 10 minutes, in which the infiltration rate showed a sharp decreasing trend; during 10 to 30 minutes, the infiltration rate decreased slowly, and remained constant after 30 minutes. By analyzing the soil infiltration rates and infiltration amount, soil infiltration characteristics of the Koeleria asiatica community were the best, followed by those of the Leymus chinensis community, while those of the Convolvulus ammannii community was the worst. The differences in soil infiltration characteristics were caused by the differences in soil structures among communities. Correlation analysis showed that bulk density, maximum porosity, and non-capillary porosity were important factors affecting soil infiltration. Soil infiltration in the study area fitted thr Honton model very well.