To investigate the therapeutic effect of arginine on burn, a randomized controlled trial in 20% TBSA deep partial-thickness burned rats was designed. The rats' wound healing, cellular immunity and nitrogen balance were evaluated at appointed postburn days. The results showed that the arginine group got better wound healing and faster recovery of cellular immunity, and achieved positive nitrogen balance. These suggest that supplement of exogenous arginine after burn may be beneficial to the victim in promoting would healing, reducing postburn immune suppression and enhancing anabolism of protein.