Abstract: The aim of the present study was to explore the differences of quality and antioxidant activity of royal jelly in different flowering periods. The contents of 10-hydroxy-2-decenoic acid (10-HDA), total protein, moisture, and total phenolic acid in royal jelly from the same conditions were analyzed, and the in vitro antioxidant activities were also compared by DPPH method and FRAP method. The results showed that there were significant differences (P<0.05) in 10-HDA contents of royal jelly during different flowering periods, and the content of 10-HDA was the highest in grape royal jelly. The contents of total protein in royal jelly ranged from 13.58% to 15.26%. The contents of moisture in royal jelly were lower than 67.5%, which met the requirements of national standard (GB 9697-2008) regarding to the moisture content of premium royal jelly. Compared with other royal jelly at flowering periods, the total phenolic acid content, DPPH radical scavenging ability and total antioxidant capacity of Vitex royal jelly were the best. And the DPPH free radical scavenging rates of royal jelly at different flowering periods were significantly different (P<0.05). The correlation analysis results showed that the DPPH radical scavenging ability was significantly correlated with the total phenolic acid and the total antioxidant ability (P<0.01).