Experiment Ⅰ. Twenty-eight rats were randomly assigned into Near-Infrared Information Radiation (NIIR) group and control group. Two weeks later each rat was innoculated intraperitoneally with Salmonella typhosa H antigen (HAg) and cyclophosphamide (CY). Peripheral lymphocyte counts in the NIIR group were significantly higher than those in the control group on the fifth day after administration of CY. Experiment Ⅱ, Fifty-four rats were randomly divided into NIIR group given CY and H Ag intraperitoneally, CY and H Ag group and H Ag group for treatment. By the end of the fourth week, the survival rate and serum IgG level in the NIIR group were significantly higher than those in the CY and HAg group. By the end of 2nd week, the titer of the anti-H antibody of the HAg group and NIIR group was significantly higher than that of the CY and HAg group. Experiment Ⅲ. Thirty rats were randomly allocated to NIIR group and control group. Spleen cells were taken and cultured with Con A for 24h to induce IL-2 and the activity of IL-2 in the NIIR group was significantly higher than that in the control group. The NK activity in NIIR group was higher but not significant and ADCC in the NIIR group was significantly higher than that in the control group. The results suggest that NIIR is capable of enhancing immunoreaction in immunosuppressive bodies by promoting the function recovery of T helper cells, therefore NIIR is effective to regulate the immunological function on chronic active hepatitis.