38 cases of Benign Monoclonal Gammopathy (BMG) representing 17.9% were screened from 212 cases of M-proteinemia by laboratory examinations. Among the 38 cases, 17 cases had increase of IgG, another 17 cases of IgA and 4 cases of IgM. Their average M-proteins were 1.42, 0.88 and 1.84 g/dl respectively.The salient points of differential of benign or malignant M-proteinemia were also discussed. The recommended sequential laboratory diagnostic procedure of BMG were as follows: tatol serum protein determination, plasma protein zone electrophresis, urine protein analysis, immunoglobulin quantitation and immunoelectrophresis or selective electrophresis.