The purpose of this study was to investigate the relationship between 30-m sprint running time and muscle cross-sectional areas of the psoas major and lower limb muscles. In sixteen male college short and middle distance runners, the muscle anatomical cross-sectional areas (CSAs) of the psoas major, the quadriceps femoris, the hip adductors (ADD), the hamstrings, the triceps surae, and the tibialis anterior and extensor digtrum longus complex (DF) were measured using a magnetic resonance imaging system. In addition, the relative values of CSA to the two-thirds power of body weight (CSA-to-BW^2/3) were calculated. A stepwise multiple regression analysis produced a prediction equation (R²=0.605) of 30-m sprint running time with explanatory variables of ADD CSA-to-BW^2/3 and DF CSA. The ADD CSA-to-BW^2/3 had a negative partial regression coefficient (r=−0.768, p<0.01) and the DF CSA had a positive partial regression coefficient (r=0.526, p<0.05). From the present results, it is concluded that to have greater hip adductor muscles relative to the body size and smaller dorsiflexors is advantageous for achieving higher performance in 30-m sprint running.<br>