Hybrid rice seeds of ‘Shenliangyou 5814’,coated with 2.5% imidacloprid-prochloraz,3% hymexazole-prochloraz,Cruiser or Celest were cultivated with pots,and the antioxidant enzymes activities,malonaldehyde(MDA) content,reduced glutathione(GSH) content,chlorophyll content and chlorophyll fluorescence parameters in seedlings were determined.The results showed that:(1)The seed-coating agents could promote the activities of the antioxidant enzymes of rice seedlings.On the 14th day after sowing,SOD activities of seedling leaves treated with 2.5% imidacloprid-prochloraz and Cruiser were increased,and POD activities of seedling leaves treated with 3% hymexazole-prochloraz were also increased.On the 22nd day after sowing,CAT activities of seedling leaves treated with 2.5% imidacloprid-prochloraz and 3% hymexazole-prochloraz were increased.On the 26th day after sowing,CAT activities of seedling leaves treated with Cruiser and Celest were increased.2.5% imidacloprid-prochloraz and 3% hymexazole-prochloraz significantly promoted MDA contents of seedling leaves on the 22nd day after sowing.All the four seed-coating agents promoted GSH contents of seedling leaves.Among them,the promotion effect of 3% hymexazole-prochloraz was most obvious.(2)The four seed-coating agents reduced chlorophyll contents of seedling leaves,but chlorophyll contents returned to normal level with time.(3)The four seed-coating agents showed no significant influences on φP_o values of seedling leaves,while the performance index PI_ABS values did not decline.The phenomenological energy flux ABS/CS_M values declined with time.Among them,ABS/CS_M values of seedling leaves treated with 3% hymexazole-prochloraz declined most obviously.Meanwhile,the dissipated energy DIo/CS_M values of seedling leaves treated with 3% hymexazole-prochloraz were significantly higher than that of control.The study indicated that the seed-coating agents caused stress to rice seedlings,and the defense system of plant reduced the damage to keep the seed-coating agents in safe level,but 3% hymexazole-prochloraz showed a relatively poor effect.