This study was conducted to assess the effects of mugwort powder (3% and 5%) on sponge cake made with medium and cake flour. After preparing sponge cakes with mugwort powder, the water activity (Aw), softness and color of crumbs were tested and the sensory properties were evaluated. The water activity of the sponge cakes containing different quantities of mugwort powder did not differ greatly. The springiness and hardness of the sponge cakes with mugwort powder were all lower than that of the control. With regard to the color of the sponge cakes, the L values were reduced, but the a and b values were increased in response to the addition of mugwort powder, resulting in the sponge cake containing mugwort having a darker color. The micrographs of the sponge cakes with mugwort powder showed a slightly lower porosity than the control. In addition, the results of the sensory test showed that cakes containing mugwort powder had low scores. However, it is still possible to make the sponge cakes using mugwort powder and the sponge cakes prepared with flower containing 3% of mugwort powder had better evaluation than those prepared using other amounts of mugwort powder.