Abstract: The optimum harvesting period and fresh-maintaining technique of sweet corn in post-harvesting period have been probed by analyzing the moisture and sugar content in fresh ears of sweet corn. The results showed that the optimum harvesting period for sweet corn was at 18~21days after in semi-nation in spring, 20~25 days in autumn. The packing way and storing temperature greatly affected the quality of the fresh ears of sweet corn in post-harvesting storage. The best way is to use vacuum packing and store at low temperature in order to post pone the fresh-maintaining period.