Rhabdomyosarcoma, relatively rare tumor occurring at mesenchymal cell, is extremely malignant. In view of the fact that most human skeletal muscle is composed of striated muscle, it is infrequent in incidence. But this tumor has high incidence as child's head and neck tumor. In particular, embryonal cell type is known to be relatively frequent. It is believed the reason is that striated muscle is completely differentiated before birth and mitosis does not occur after birth. The favorite site of this tumor are in order of head, neck, genitourinary system and both extremities. Particularly embryonal cell type is very rapid in growth and high in recurrence and the prognosis is poor. It is reported that this tumor has high mortality within a year after being involved. We reported a case of rhabdomyosarcoma involving the left cheek in a 5-year-old boy whose duration is about 2 years and 6 months.