Abstract:Studies on the seedling quality of Larix gmelini,L.olgensis and L.principis and ecological factors during the growing season were carried out in Shuiling Nursery,Hei long jiang Province for 4 years consecutively.In the population studies and analysis on light requirement of root content of dry matter and nutrient content of leaves were conducted.The relationship between population structure and quality of seedlings has been made clear.The scientific techniguc for breeding Larch seedlings of high quality has been put forward.