Abstract: A 7-year-old male Lhasa dog was treated in an animal hospital due to a small lump on the cheek. The initial diagnosis was carried out by the examination methods of medical history investigation, clinical examination, blood routine, blood biochemical indexes, cytology and histopathology; and the treatment was performed according to the preliminary diagnosis results. The results showed that the cheek lump was a basal cell tumor that had progressed to stage T2, without regional lymph node or distal metastasis. The dog underwent surgery to remove the tumor on the cheek and received drug therapy at the same time. The dog recovered well after surgery. The follow-up visits were made affter 1, 3 and 6 months of discharge, and no recurrence was found. The results suggested that canine basal cell tumor could be completely cured by radical surgery if it was found and diagnosed early.