Abstract: Seed kernels at various developmental stages were used as experimental materials to systematically study the accumulative procedure of storage substances and change trend of component contents.It was showed that the seed kernel accounts for 4.8% of dry weight of the ripen cone and its storage substances change with the embryo development. The contents of gross fat, gross protein and total carbonhydrate of ripen seed kernels are 44.8%,42.5% and 6.54% respectively,while starch and soluble carbonhydrate account for 4.26% and 2.88% respectively. Enzymic protein content decreases from the maximum at early phase of proembryo stage(20.83%)to the minimum at young embryo(4.9%). Here the fat of the seed kernels consists of four kinds of fatty acid,of which the content of unsaturated fatty acid is much more than each one of the saturated fatty acid. Lindeic,oleic,palmitic and stearic acid accounting for 65.7%,21.7%, 9.2% and 3.4% of the total fatty acid respectively.It was found that seed kernels of masson pine contain mainly 16 kinds of amino acid,of which the minimum content of the 14 kinds appears at the proembryo stage and the maximum content of the 10 kinds at the early phase of young embryo stage.Among 16 kinds of amino acid,the contents of arginine,glutamic and aspartic acid are higher(from 3.0% to 7.5%),and lysine,tyrosine,histidine,cystine and methionine the lower(1%).