Seed vigor and physiology of Luliangyou996 were determined through aging treatment with 40 ℃ and 100% relative humidity artificially. It showed that: the germination rate,germination energy and germination index of seed when it was harvested in 8─12 d after the ending of flower of female parents, increased and then changed a little in 13─17 d, decreased significantly and lost the value after 18 d after aging treatment. The starch content reduced after aging treatment, especially the seed harvest after 14 d; CAT activity of the harvested seed in 13─17 d reduced most quickly; MDA content of the harvested seed in 11─17 d had little difference,but that of the harvested seed was much higher in 8~10 d or after 18 d.