Abstract: This study was conducted to investigate the effect of monosodium L-glutamate ( MSG) and high-fat ( HF) diet on carcass character and composition in growing pigs.Thirty- two growing pigs with an initial body weight of25.0kg were allocated into four groups, randomly, including basal diet group, MSG + basal diet group, HF diet group, and MSG + HF diet group. The carcass character and composition were determined after a 30d feeding.Result showed that total fat rate, ratio of hind leg to hip, scores of meat color and muscle marbling in HF diet group were higher ( p < 0.05) , as well as contents of intramuscularly lipid and monounsaturated fatty acid of biceps femoris, while total bone rate and polyunsaturated fatty acid content of biceps femoris were lower ( p < 0.05) , when compared with the basal diet group; total fat rate, ratio of hind leg to hip, scores of meat color and muscle marbling, and intramuscularly lipid content of biceps femoris in MSG + basal diet group were higher ( p < 0.05) than that in the basal diet group; MSG supplementation in HF diet decreased ( p < 0.05) the ratio of hind leg to hip, contents of intramuscularly lipid and unsaturated fatty acid of biceps femoris while increased ( p < 0.05) the content of saturated fatty acid than that of the HF diet group. These findings indicated that dietary supplementation with MSG could improve carcass character and composition in growing pigs.