The experiment was conducted to investigate the effects of PPARγ agonist or antagonist on white blood cell differential count and blood biochemical indexes of weaned piglets with lipopolysaccharide (LPS) challenge. Twenty-four weaned piglets were allotted to 4 groups (6 replicates per group and 1 piglet each replicate), including control group, LPS group, rosiglitazone (ROS, PPARγ agonist)+LPS group and bisphenol A diglycidyl ether (BADGE, PPARγ antagonist)+ROS+LPS group. Blood samples were collected at 3 h post-challenge of LPS. The results showed as follows: 1) ROS alleviated the decrease of white blood cells and lymphocytes counts of weaned piglets induced by LPS (P<0.05). BADGE inhibited the effects of ROS on white blood cells (P<0.05); 2) ROS alleviated the increase of alkaline phosphatase activity (P<0.05) and the decrease of total protein, albumin and globulin content (P<0.10) of weaned piglets induced by LPS. And BADGE inhibited the effects of ROS (P<0.10). These results indicated that ROS alleviated the decrease of white blood cells and lymphocytes counts and change of some blood biochemical indexes of weaned piglets induced by LPS to some degree, and BADGE blocked the effects of ROS.［Chinese Journal of Animal Nutrition, 2010，22（1）:145-150］