Lymphocytapheresis (LCP) was performed in 7 patients (1 male and 6 females) with HAM to delete lymphocytes from their peripheral blood, resulting in an improvement of motor disability in 6 of 7 patients with HAM. The therapeutic effect appeared within one day after first LCP, and reached maximum in 2 or 3 sessions of LCP. The side effects were only dysesthesia in 5 patients during LCP and mild leukopenia in a patient after LCP. Both of them were mild and transient. The effect of LCP continued for two to five months in 6 patients, the remaining one deteriorated in a month. In the study of T cell subsets of peripheral blood lymphocytes by flowcytometry, the CD4/8 ratio and the cell counts of CD4+ DR+, CD8+ DR+ and IL-2R positive cells were gradually decreased by LCP. These results suggest that LCP is one of the effective therapies for HAM and peripheral blood lymphocytes implicate in the pathogenesis of HAM.