Marjolin's ulcer seated upon an old cicatrix, especially old burn scar, which may chiefly degenerated into a squamous cell carcinoma with propensity for metastasis. We are experienced two cases of Marjolins ulcer recently. A 54-year-old male who had a Marjolins ulcer(15x40cm) on his left lower extremity. He was experienced burn at the age of eight and rice sized ulcer was developed at the site of burn scar about 21 years ago. The ulcer progressively enlarged in size to reach 15x40cm for 21 years. The pathologic diagnosia was squamous cell carcinoma grade 1, but cancer cells invaded to deep dermie and subcutaneous tissues. Severe skin lesion and irreversible osteoporotic degeneration on knee joint of affected limb were present. So he was treated by high above knee amputation. Another 58-year-old female who had a Marjolins ulcer(10x20cm) on her right lower extremity. She was experienced burn at the age of forty eight and bean sized ulcer was developed at the site of burn scar about 1 year ago. The pathological diagnosis was squamous cell carcinoma grade 1 and invasian of cancer cells was limited upper dermis. On lymph node biopsy, the histological diagnosis was within normal limit. So she was treated radical surgical excision with split thickness skin graft(Mesh).