A 46-year-old women presented with giant congenital melanocytic nevus on back and abdomen including many satellite lesions on legs since birth. From last 3 years, whitish patches occurred on face, hands, feet and back. The depigmented patches also spread even on nevus lesion. She had no remarkable past history, family history or any drug history. The wood lamp examination showed sharp demarcation with accentuation on whitish patches. The biopsy from depigmented patch showed absent melanocytes, and excisional biopsy from depigmented nevus lesion revealed compound nevus with decreased melanocyte on epidermis. The abdomino-pelvic CT and brain MRI had no other abnormal finding, and laboratory examination including thyroid function test was within normal limit. Vitiligo vulgaris is an acquired hypopigmentary disorder results from melanocyte destruction. The exact etiological factor is still not known, but the autoimmune mechanism medicated by T cells is well accepted. The halo formation or vitiligo with cognenital melanocytic nevus lesion may also indicate immunologic reaction about nevus cells. This case shows rare vitiligo vulgaris developing in giant congenital melanocytic nevus.