The tissues of gluteal region including skin and underlying gluteus maximus muscle are used for reconstructions of head and neck deformities caused by trauma and lumbosacral defects caused by bed sores, and for reconstruction of breast. Moreover, gluteus maximus flaps were used for reconstruction of anal -and vaginal -sphincter dysfunctions after radical resection for treatment of cancer in anorectal or vaginal region. Because the knowledge on the precise course and branching patterns of the arteries supplying the gluteus maximus muscle enables the prediction of the safety of surgery, the perforating branches supplying skin and subcutaneous tissues which exited from the gluteus maximus muscle, the positions of the superior and inferior gluteal arteries exited from pelvic cavity under the gluteus maximus muscle, and the course of these arteries under surface of the muscle were investigated. Total ninety -one dissected gluteus maximus from 47 Korean cadavers (44 bilateral specimens and 3 unilateral specimens) were observed. The perforating branches exited from the gluteus maximus were divided into upper and lower parts. The superior gluteal artery supplied upper two fifth of gluteal region and the inferior gluteal artery supplied the rest of gluteal region. The positions of superior and inferior gluteal arteries exited from pelvic cavity were in 1 cm medial to upper one third point on connecting line from posterior superior iliac spine to greater trochanter of femur, and middle point on connecting line from posterior superior iliac spine to ischial spine, respectively. The courses of the superior and the inferior gluteal arteries were classified into four types by distribution patterns. The most common incidence (46.5%) was observed in the typical type (Type I) that the superior and inferior gluteal artery supplied the upper or lower part of gluteus maximus muscle, respectively. The incidence of type II that some branches of inferior gluteal artery run up to the area supplied by superior gluteal artery was 16.3%. In contrast to type II, the incidence of type III that some branches of superior gluteal artery run down to the area supplied by inferior gluteal artery was 18.6%. The incidence of Type IV that only superior gluteal artery supplied the muscle was 18.6%.