Abstract: The soil moisture properties of the major stand types of young plantations of Platycladus orientalis after having been tended in the mountainous area of Beijing were studied by means of setting up investigation plots and fixed observation station techniques, it was showed by the results that: There was an exponential function relationship between the soil moisture under the tended Platycladus orientalis plantations and the water absorbing capacity of the soil.Forest tending could increase the water holding capacity of the soil, and the increment of water holding capacity was positively proportional to the forest tending intensity.Forest tending could also increase the water supply ability of the soil.The water supply ability increased along with the increment of forest tending intensity.