Phosphorus,which mainly exists in organ-phosphorus status,can be enriched in seed during the development of soybean.However,there are a few research reports on the effects of storage phosphorus in soybean seed on the growth of soybean seedlings.‘Baxi 10’ (B10) and ‘Bendi 2’ (L2),two kinds of soybean varieties with the differences in seed size and phosphorus efficiency,were used to investigate the status changes during the development of soybean using sand culture with different nutrition solutions.The total phosphorus contents,concentration of soluble phosphorus in main organs and the contents of soluble proteins,acid protease activity,phytase activity in leaves were determined during the seed germination stage to 2nd trifoliate stage in different phosphorus conditions.The results showed that:(1)The phosphorus contents in seeds of B10 and L2 are significantly different.(2)Most phosphorus in the cotyledons were transferred to roots,stems and leaves during the processes of soybean germination and seedling growth,while most phosphorus in the cotyledons was transferred to leaves.The total phosphorus of B10 transferred from cotyledons to other organs was different from that of L2 during the process of soybean germination.(3)The transfer of phosphorus in cotyledons was distinctly influenced by the content of phosphorus solution.The results also showed that there existed in a complementary relation between phosphorus in cotyledons and leaves,and the contents of total phosphorus in organs with phosphorus supply conditions were higher than that under the conditions without phosphorus supply.The acid phosphatase activity of B10 in cotyledons under low phosphorus supply condition was much higher than that under high phosphorus supply condition,while there was no difference of acid phosphatase activity of L2 under low or high phosphorus supply condition.All the results suggested that the storage phosphorus in the cotyledons played important roles in the process of young seedling.