Abstract: Objective :To compare the clinicopathological features of mucosa associated lymphoid tissue (MALT) and extranodal diffuse large B-cell yell lymphoma and investigate some factors associated with their prognosis. Methods : Ninety-four cases of extranodal B-cell lymphomas (including 62 cases of mucosa associated lymphoid tissue lymphoma and 32 cases of extranodal diffuse large Bcell lymphoma) were retrieved. The clinicopathological data about the cases were collected and follow-up study was done. Results :As compared to extranodal diffuse large B cell lymphoma, the incidence of mucosa associated lymphoid tissue lymphoma was low with regard to the median age, staging, frequency of relapse, involvement of lymph node, and cellular proliferation index. The survival status was better in the patients showing a low cellular proliferation indexto 20%, stage I E and no involvement of lymph node, whereas the survival status was worse in those showing a higher cellular proliferation index(>20%) and stage (above I _E)as well as the involvement of lymph node. Conclusions :There is statistical difference between the mucosa associated lymphoid tissue lymphoma and the extranodal diffuse large B cell lymphoma in the aspects, i.e. the median age, cellular proliferation index, staging, involvement of lymph node, relapse rate and prognosis. The prognosis for both types of lymphomas relates to the cellular proiferation, staging and the involvement of lymph node.