Soil physical properties and water conservation of Natural Quercus mongolicaforest were studied atdifferent slope positions in the mountainous area of Northern Hebei Province.The results showed that soilbulk density,soil non-capillary porosity,and effective water storage at the upper 40cm soil layer varied atdifferent slope positions,in a descending order as middle slope>lower slope>upslope.Soil bulk density varied between 1.0g/cm³ and 1.1g/cm³.The means of soil non-capillary porosity and effective water storageamount were 8.9%and 347.6t/hm²,respectively.Soil capillary porosity,total porosity,soil capillary waterstorage and maximum water storage at different slopes had average values of 38.5%,47.5 %,1 521.5t/hm²,and 1 869.1t/hm²,respectively,with the highest values at lower slope and the lowest at upslope.The litter thickness,total litter and maximum water storage had averages of 48.7cm,23.6t/hm²,and 49.3t/hm²,respectively,and can be ranked in terms of slope positions as:lower slope>upslope>middle slope.Maximum water holding capacity varied from 219.34%to 231.8%,exhibited highest values at upslope,followed by middle slope,and then lower slope.Water storage of the forest at different positions can be arranged in a descending order as:lower slope(1 996.0t/hm²)>middle slope(1 930.0t/hm²)>upslope(1 829.3t/hm²).The average value of water storage was 1 918.4t/hm².The results indicated that waterstorage capacity of natural Quercus mongolicaforest was significantly affected by slope position.