Two patients with K-type IgG myeloma are reported. These patients were admitted to the Mitoyo General Hospital and studied for long periods. Case 1: 56 year-old woman, had typical bony lesions and atypical plasma cell proliferation in the bone marrow. Bence-Jones protein in her urine was negative. The serum IgG level was 4.38g/dl. She survived for 29 months after the diagnosis. Case 2: 85 year-old man, survived for 41 months after the diagnosis was established. There was no bony lesion in X-Ray examination. Uninary Bence-Jones protein was negative. 16.6 % of atypical plasma cells were found in the bone marrow. Serum IgG level was 3.3g/dl.