This is an analysis and review for 17 cases of multiple myeloma, 1 case of plasma cell leukemia and 1 case of adult Fanconi syndrome, which have been encountered in. this laboratory during the last 10 years from 1964 to 1975, July. The following results are obtained in analysis of 17 cases of multiple myeloma. 1. The sex ratio was predominant in male, being 4.7 : 1 and the mean of age distribution was 15 years, ranging from 34 to 73 years. 2. The most frequent complaints at the time of admissions were the bony pains (77%), symptoms due to anemia (53%), and symptoms due to hypercalcemia (35%). 3. The means of hemoglobin and ESR were 7.5gm% and 62mm/hr, respectively and the peripheral plasma cells are found in 47% of the cases, ranging 4.5-95% in number of differential counts. 4. The mean of myeloma cell distributions in bone marrow was 46.3%, ranging from 4.5-95% in number of differential counts. 5. Serum M-components were detected in 10 cases among 13(77%) and 7 cases of them were known to be IgA (4) and IgG (3) by immuno-electrophoresis or radial immunodiffusion method. 6. Bence-Jones proteinuria was present in 8 cases (50%) among 16. 7. Multiple punched-out osteolytic lesions were found in 12 cases (85.7%) among 14 by radio-logical bone series. The one case of plasma cell leukemia disclosed 76,400/mm3 in W.B.C. count with 51% of plasma cells in peripheral blood, and the one case of adult Fanconi syndrome revealed atypical plasmacytosis (10%) in bone marrow, but no M-component is identified.