The purpose of this study is to measure the comparative abdominal muscle activation during straight leg raise according lumbar supplement thickness and angle of leg raise. Healthy 14 male and 16 female adults, 30 people in total were recruited. When straight leg raise, lumbar supplement thickness and angle of leg raise. We measured abdominis with ultrasonograpy. All measurements of the experiments were performed by two-way ANOVA. According to a study when exercise straight leg raise, there are no interaction between lumbar supplement and angle of leg raise. But when apply only lumbar supplement or apply only angle of leg raise, external oblique and rectus abdominis are show statically significant. It is considered exercise straight leg raise with lumbar supplement or apply angle of leg raise are effective way for selective abdominal muscle exercise.