In order to assess water conservational function of different forests types in Laotudingzi natural reserve,six forest soils were selected to test soil storage capacity and infiltration characteristics.The results indicate that soil bulk density(0-40cm)under these forests ranged from 0.76to 1.71g/cm^{3,non-capillary porosity ranged from 8.15%to 22.07%,capillary porosity ranged from 27.060%to 53.28%,soil porosity conditions of natural secondary forests,such as shrub,Betula ermanii,Spinney,were better thanLarix pricepis-ruprechtii andPinus koraiensis, soil water storage(0-40cm)ranged from 1 429.8 to 2834.3t/hm2,effective capacity ranged from 325.9to 882.7t/hm2,capillary water holding capacity ranged from 1103.8to 2131.0t/hm2,soil wate-holding capability of natural secondary forest was relatively stronger than plantation, initial infiltration rates(0-20cm)ranged from 0.28to 21.1mm/min,and initial infil-tration rates(20-40cm)ranged from 0.07to 6.7mm/min,steady infiltration rates(0-20cm)ranged from 0.14to 8.3mm/min,steady infiltration rates (20-40cm)ranged from 0.05to 2.0mm/min,initial infiltration rates and steady infiltration rates of natural secondary forests were relatively stronger than plantation.A power function can be used to describe the relationship between soil infiltration rate and time.}