Abstract: According to the observation data of artificial Mongolian pine plantations in Zanggutai, Liaoning Province from 1979 to 1985, the soil water distribution, its rule of changes and their quantitative relationship were analysed in this article.The results showed that the soil water content in the pine plantations gradually decreased and was 1.08% lower in the 25-years stand than that in the treeless control area. Water consumption through tree transpiration, which accounted for 34.75%—71.4%of the precipitation and 60.8%—71.7%of the total amount of water consumption in the same period, was the principal way of water loss and the main factor inducing water deficiency.Reasonable thinning of the stand and soil cultivation might improve water conditions and play an important role in regulating water content. Besides, the yearly precipitation in Zhanggutai in arid years is equal to that in the Keerqin sandland district in normal years. To develop large scale plantations there might cause water deficiency. It was advisable to afforest strip-shapedly or patch-shapedly on the lower part of the dune or the low land between two dunes, but not on the upper part of the dune. In this way water equilibriun may be attained and affore-station may be successful.