Abstract: The length,width,volume and weight of Ginkgo biloba seed were measured,and the concentrations of water,sugars,fatty acids and amino acids in seed growth process were analyzed.A typical “S” seed growth curve was found,and the length,width,volume,weight and absolute water content all showed the similar changes during growing period.With the growing of ssed,the concentrations of physiological substances in seeds showed regular changes and had their own characteristics.The total amount of sugars appeared to be an increasing trend at the later stage of seed growth,indicating that sugars are the main nutrition substance accumulated in seeds.The concentrations of various substances in matured seeds were starch 8.4%,glucose 6.7%,fructose 4.2%,polysaccharide 0.02%,disaccharide 0.01%,myristic acid 10.6%,palmitic acid 4.1%,flax acid 2.4%,stearic acid 1.9%,oleic acid 1.1%,and linoleic acid 0.4%.Fifteen types of free amino acids were detected in matured seeds,with total content of 1.56g·100g^-1 FW.Among them,lysine aspartic acid,alanine,arginine,histidine,glutamic acid,and isoleucine were dominant,and their concentrations were 0.287%,0.163%,0.136%,0.133%,0.123%,0.115%,0.095%,respectively.