RÉSUMÉ
In order to investigate an effects of the hot spring within a short period on immune system of human, the leukocyte, monocytes, lymphocyte and lymphocyte surface markers: CD2, CD4, CD8, CD16, CD19 and CD57 were tested in the human peripheral blood of twenty-three healthy volunteers by hot spring bathing. The results were as follows: Total number of leukocytes and lymphocytes in the peripheral blood significantly increased in an older group after hot spring bathing (p<0.01). However, we obtained a clear decrease in the number of granulocyte after hot spring bathing in the younger group (p<0.01). In addition, we found greater increase of the CD16<sup>+</sup> cell counts and a clear decrease of the CD19<sup>+</sup> cell counts in older group. But in younger group, we also obtained an increase of CD8<sup>+</sup>, CD16<sup>+</sup> cells after hot spring bathing. These results indicated that hot spring bathing can regulate the physical immune system.<br>According to the percentage of lymphocytes or granulocytes in the total leukocytes, volunteers were divided into two types, more than 70% of granulocyte were recognized as G type and more than 40% of lymphocyte were divided in the L type. We found an increase of lymphocyte and lymphocyte subsets as well as a decrease in granulocyte in G group by hot spring bathing. But in L group, especially, indicated a greater increase in granulocyte and a decrease in lymphocyte subsets. We suggest that hot sping bathing can regulate by an autonomic nerve system, making it suitable.