To observe the influences of different daily doses between 1-4 J/cm2 of low-level laser therapy (LLLT) on wound healings,the dorsal cutaneous excisional wounds of Wistar rats were irradiated with 630 nm at three daily doses of 1.2 J/cm2,2.4 J/cm2 and 3.6 J/cm2 under a constant power density of 10 mW/cm2. The analysis of variance (ANOVA) of areas of the wounds indicates that there were no statistical differences among the control group and the other three different doses groups. However,microscopic observations,both hematoxylin and eosin staining and Masson staining,could tell evidently better results of LLLT groups when compared to the control group,including the shorter period of inflammation,the greater development of granulations and collagens,and better epithelialization. The microscopic evaluations also suggest that larger dose brings better wound healing results within the 1-4 J/cm2 range.