One case of primary malignant lymphoma of the central nervous system is reported. The patient, a nine year old boy having headache, vomiting, seizures in the right limbs and unconsciousness, was admitted into our hospital and died the next day. A tumor at the base of the left frontal lobe was found on autopsy. There was no evidence of tumor elsewhere. A pathological diagnosis of T-cell malignant lymphoma was established. In this paper, the view that the T-cell lymphoma can arise from the central nervous system is proposed for the first time. Its clinical features, pathomorphology and histogenesis are discussed. Yet, how follicles are formed in the tumor tissue and its significance await further study.