One hundred eight Hanwoo cows were evaluated ultrsonically for longissimus muscle depth and muscle width over the 13th rib before slaughter. Carcass measurement of muscle area, muscle depth and muscle width were also obtained. The correlation coefficient between muscle area and muscle depth were 0.78 while correlation coefficient between muscle area and muscle width was 0.51. A linear regression model to predict muscle area(y) by ultrasonic measured muscle depth(x) was developed as follows: y=15.2 + 7.17 x, (R²=0.44).