Soil hydrological characteristics were studied for four typical forest ecosystems located in Beijing mountainous area.Results showed that soil bulk density increased with the increase in soil depth,while total soil porosity and capillary porosity decreased.There was no regular trend for non-capillary porosity.Soil water potential at all levels increased with soil water content for all forest stands and 100kPa was found to be the cutoff value of the characteristic curve of soil water.The transient phase of infiltration occurred in the first five minutes,the gradual phrase occurred between the fifth minute and the sixtieth minute,and the stable phrase occurred after 60minutes.Infiltration capacity of coniferous forest soil was significantly higher than that of broad-leaved forest.Jiang Dingsheng formula best fitted the infiltration process determined by double-ring method.