Skin basal cell carcinoma may or may not be carcinoma in situ, and they are not the same concept. Skin basal cell carcinoma is based on the origin of lesion, while carcinoma in situ is the stage of lesion. Basal cell carcinoma of skin refers to malignant tumors originated from basal cell of skin, and the corresponding tumors occur in head, face, etc. The specific stage needs to be further investigated, and it does not necessarily belong to carcinoma in situ; the so-called carcinoma in situ refers to the tumor cells are only limited to the mucous epithelial cell layer, which is a kind of the earliest condition of the lesion; the two are not the same concept, and they can not be equated. After the discovery of basal cell carcinoma of the skin, it is necessary to carry out further examination and clinical examination for the staging of the disease, and carry out standardized treatment under the guidance of doctors.