Soil culture experiment on the effects of soil texture,water supply and tuberele-bacteria inoculation on Albizzia falcata seedlings was conducted and the activity of nitrogen-fixing enzyme measured.Results showed:1.Medium loam and sandy loam were favorable to seedling growth and tobercle formatio n while hard and clayey soilwith sand content less than 16.6% inhibited growth;2.There was a great differencein the results of tuberde-bacteria inoculation among different soil textures,the bestbeing medium loam and sandy loam;3.Measurement suggested that the long periodof low temperature and rainy humidity might have caused the low activity of nitro-gen-fixing enzyme in the tubercles.For definite conclusion,further study is needed.