Purpose : This study was to investigate the effects of Dohongsamul-tang extract on the rat with an surgically induced endometriosis. Methods : Four weeks after the operation for inducing the endometriosis to a matured female rat, the normal hyperplasia of the transplanted endometrium was identified in anatomico-histological aspects. By dividing each of the control group and Dohongsamul-tang administered experimental group into 8 rats, Dohongsamul-tang concentrates were administered orally to the experimental group with 1g/1ml/200g everyday for 40 days and then images were taken from the macroscopic tissues which were transplanted to the mesenterium, and the concentrations of progesterone, estradiol, tumor necrosis $factor-{alpha}(TNF-{alpha})$, and interleukin(IL)(-2, -4, -6, and -10) in the serum were measured. Results : Transplanted endometrium tissues showed the histological findings in accordance with the normal endometrium tissues and from the macroscopic findings the size of transplanted endometrium tissues showed a definite decrease. Compared to the control group, the experimental group showed significant decreases in the values of $TNF-{alpha}$,IL-2, and IL-4 and significant increases in the values of IL-10. However, there were no significant differences in progesterone, estradiol and IL-6. Conclusion : From the above results, Dohongsamul-tang showed the strengthening of immunological function and anti-inflammatory effect. Therefore it is considered that Dohongsamul-tang will be very effective on the treatment of inflammation developed endometriosis, especially to treat the endometriosis without affecting the ovary functions.