Objective : This clinical study investigated the effect of Yeosindan on dystocia caused by abnormal expulsive forces. Methods : Yeosindan was applied on the umbilicus of a primipara who had gone through latent phase for 15hrs and was almost expected to undergo C-sec by dystocia. It was sealed with an plaster. Yeosindan was removed immediately after the delivery. Results : 1. 90 minutes after Yeosindan had been applied on the umbilicus of the primipara, the active phase dilatation of uterus was started normally. 2. After 190 minutes from the Yeosindan application, the 2nd stage of labor was finished. 3. In this case, the delivery time, of which average is 344 minutes from the active phase to the second stage of labor, was reduced by 244 minutes. 4. So far, no abnormal condition has been detected in both the neonates and the primiparas.