Malignant lymphoma is classified roughly into Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) according to the biological characteristics. Malignant lymphoma in Japan has such characteristics as low incidence of HD, which is usually favorable in prognosis, and high incidence of NHLs, which have further distinctive features of less incidence of favorable follicular B cell lymphoma and of higher incidence of unfavorable diffuse T cell lymphoma including adult T cell leukemia/lymphoma (ATLL) in comparison with those in western countries. As a recent trend of progress in lymphoma study, the introduction of molecular diagnosis by means of gene rearrangement analysis of immunoglobulin and T cell antigen receptor has contributed diagnostically to a definitive determination of T and B cell lineage and cellular monoclonality in malignant lymphoma. On the other hand, remarkable progress has been made in the treatment of malignant lymphoma in recent years. After all, in HD even far advanced cases have been expected to be curable by the combination chemotherapy, for example, MOPP regimen in USA at the present time. Furthermore, in NHL even advanced cases with such aggressive lymphoma as diffuse large cell lymphoma of B cell type have also been able to survive for more than 10 years and may be curable with the frequency of more than 30% in several institutions. Nowadays, the treatment for malignant lymphoma has focussed on multidisciplinary cure-oriented therapy including chemotherapy and radiotherapy in a collaboration of surgical procedure and immunotherapeutic maneuvers. The recent chemotherapy regimen has been called "third generation" ones characterized by alternating non-cross resistant combination and frequent administration of intense drug dose. Furthermore, various biologics such as monoclonal antibodies, several BRMs including IFNs, IL-2 and TNF, and recombinant G-CSF and GM-CSF have been applied in lymphoma treatment to improve the efficacy of combination chemotherapy in new designs of clinical trials.