Abstract: One year old seedlings of ginkgo (Ginkgo biloba L.) were grown in a pot under greenhouse conditions with varying soil water levels to determine the growth and the biomass allocation. There were 4 different treatments of’ soil water and 4 ginkgo cultivars, and the time of treatment was 100 days. The results were as follows: (1) Relative height growth,relative caliper growth, biomass increment, plant leaf area and plant root volume of ginkgo decreased with decreasing of soil water content, but shoot/root ratio of varieties increased with decreasing of soil water content (except the treatment of W4); (2)The biomass increments of root,stem and leaf of 4 varieties all decreased with decreasing of soil water content, and the order of biomass increments of root,stem and leaf of 4 cultivars was root>stem>leaf; (3) The allocation ratio of biomass increment of root increased with decreasing of soil water content, but the allocation ratio of biomass increment of stem and leaf decreased with decreasing of soil water content,and the allocation ratio of biomass increment of root was highest, and the second was stem,and the allocation ratio of biomass increment of leaf was lowest.