Recent advances in clinical research on surface marker analysis of malignant lymphoma cells are reviewed. Malignant lymphoma can be classified into T-cell malignancy or B-cell malignancy, using flow cytometry or immunohistochemical analysis. Based on recent results of immunophenotypic analysis and clinical data, a new clinicopathologic classification of lymphoid malignancy is proposed. T-cell malignancy bearing T-cell receptor of gamma delta-type is discussed. Other recent topics on malignant lymphoma, such as B-cell lymphoma of the pleural cavity developing from long-standing pyothorax, mediastinal large-B-cell lymphoma with sclerosis, HIV-related B-cell lymphoma, and EB-virus genome carrying B-cell lymphoma in ATL are also discussed.