Immunological function and lymphocytic subsets of peripheral blood mononuclear cell (PBWC) from 39 patients with scrofula were investigated before and after treatment with musk-moxa-string therapy. The results showed that the percentage of CD3+, CD4+ cells and the ratio of CD4+/CD8+ cells were markedly decreased in the patients than normal control (P less than 0.001). On the contrary, the numbers of B lymphocytes and DR+ cells were increased. But the response of PBWC to phytohemagglutin in (PHA) stimulation markedly decreased in the patients than the normal control. After treatment with musk-moxa-string therapy, the percentage of CD3+, CD4+ cells and the ratio of CD4/CD8 were increased (P less than 0.001) and blastogenic response to mitogen stimulation with PHA recovered to normal. Meanwhile, the symptoms was improved and swell lymph node disappeared or was reduced markedly in size and the ulcer was healed completely. These findings suggest that the effect of musk-moxa-string therapy is caused by the enhancement of immunological capacity of the patients.