Free -flap which is transferred to recipients is a thin flat tissue isolated from human body and nutrient vessel of free - flap is ligated with similarly sized vessel. Free -flap reconstruction is widely used, due to high rate of flap survival and functional refinements, although it gives disadvantage of long surgery time and inefficient adaptation. This study demonstrates the characteristics and arterial supply of rectus femoris muscle of thigh. Seventy thighs (35 right, 35 left) of the 35 cadavers (19 males/16 females) which were clinically normal and without deformity were dissected and measured, according to Martin measurements. 1. The average length and width of rectus femoris muscle were 396.7 +/-39.9 mm and 36.5 +/-7.9 mm, respectively. The length of female subjects was significantly different from that of male subjects (P 0.05). 2. In the origin and insertion of rectus femoris muscle, anterior tendon and posterior tendon were not different between female and male subjects. 3. Artery of the rectus femoris muscle arises from deep femoral artery. The length of pedicle from the entering point of the rectus femoris muscle was average 19.0 +/-11.9 mm. The length from the entering point of the rectus femoris muscle to spliting point was 13.7 +/-7.7 mm of P1, 12.6 +/-7.5 mm of P2, and 14.8 +/-11.63 mm of P3 pedicles. 4. The frequency of the blood vessels inserted into the rectus femoris muscle was the first highest at the portion of 32.5 ~35% and the second highest of 35 ~37.5% and 37.5 ~40% ranges, when anterior superior iliac spine from center of the patellar was considered as 100% of portion. 5. According to the method by Kimata et al. (1998) classifying perforators based on the anatomic variations, type 1 and VIII were 83.58% and 5.97% respectively. Type 5, 6 and 7 were not observed. 6. Femoral nerves inserted into the rectus femoris muscle were distributed within 7.5 ~45% portion when anterior superior iliac spine from center of the patella was converted into 100%. The portion of 17.5 ~20% had the highest frequency of nerves. In conclusion, length of the rectus femoris muscle in Korean were different depending on gender, whereas tendon lengths were not. These data demonstrate artery pattern in Korean and provide anatomical potential for rectus femoris muscle to be used as a free -flap muscle.