It has been known from studying on 37 forest types that the water storing level of forest in Hunan province is very low .The average total quantity of water storing is 4102.9 t/hm²,and the effective quantity of it is 830.2t/hm²; The largest effective quantity of water storing in natural forest,artificial forest and ecological forest of simulating natural reaches 1049.7 t/hm²,534.5t/hm² and 764.0 t/hm² respectively. The largest effective quantity of water storing of natural forest,middle-age forest and young growth forest of natural forest reaches 1285.1/hm²,1065.4/ hm²and 798. 5 t/hm² respectively;The 3 ages classifacation of artificial forest are 642.5t/hm²,563.0 t/hm² and 534.5 t/hm². The techniques for water preserving capability improving in forest land were advanced acxeording the low quality and its low function of water storing.