Purpose : This study examined effects of Paljin-tang on endometriosis. Methods : Sugically induced endometriosis in rats were given an oral dose of Paljin-tang for 40 days. The size of the ectopic uterine implants at the serosal wall and the concentration of progesterone, estradiol, tumor necrosis factor(TNF)-${alpha}$ and interleukin(IL)-2, IL-4, IL-6, and IL-10 in the blood were examined and compared with the control group. Results : The size of the ectopic uterine implants in the experimental group was much smaller than of that in the control group. The concentration of estradiol was significantly lower in the experimental group than in the control group. The TNF-${alpha}$, IL-4, IL-6 levels was significantly lower in the experimental group than the control group and IL-10 level was higher in the experimental group than the control group. The progesterone, IL-2 levels were similar in the experimental and control groups. Conclusion : These results indicate that Paljin-tang reduces the size of ectopic uterine implants at the serosal wall and inhibits the growth of ectopic uterine implants. This suggests that Paljin-tang is an effective treatment for endometriosis.