Objective To investigate the effect of aerobic and resistance exercise on immune functions in SAMP8 mice. Methods Twenty-eight-week-old male SAMP8 mice were divided into a model group, aerobic exercise group and resistance exercise group, with eight mice in each group. Another eight SAMR1 mice of the same age were used as the control group. The aerobic exercise group received 8 weeks of uniform horizontal exercise running platform training, and the resistance exercise group received 8 weeks of increasing weight climbing exercise training. The relative grip strength and rotarod test were performed every 2 weeks. The index of immune organs was measured. The histomorphology of immune organs was observed, and the serum IL2 concentration was measured by an ELISA. Immunohistochemistry was used to detect expression of IL2Rα protein in the spleen. RT-qPCR was used to detect gene expression of IL2, IL2Rα, IL2Rβ, and IL2Rγ in the spleen. Results Compared with the control group, the relative grip strength and rotarod test time of model group were decreased significantly (P< 0. 0001). Thymus and spleen indexes were decreased significantly (P< 0. 001). Aging of immune organs was observed. The serum IL2 concentration was decreased significantly (P< 0. 0001). The positive rate of IL2Rα protein in the spleen was decreased significantly (P< 0. 001). Gene expression of IL2, IL2Rα, IL2Rβ and IL2Rγ in the spleen was decreased significantly (P< 0. 01). After 8 weeks of aerobic and resistance exercise, compared with model group, the relative grasping strength and the rotarod test time of aerobic exercise and resistance exercise groups were increased significantly (P< 0. 05). Compared with aerobic exercise group, the relative grasping strength of resistance exercise group was increased significantly (P< 0. 05). Thymus and spleen indexes of aerobic exercise and resistance exercise groups were increased significantly (P< 0. 05). Delays in aging of immune organs were observed. The serum IL2 concentration in aerobic exercise and resistance exercise groups was increased significantly (P<0. 01). The positive rate IL2Rα protein in the spleen in aerobic exercise and resistance exercise groups was increased significantly (P< 0. 05). Gene expression of IL2, IL2Rα, IL2Rβ, and IL2Rγ the in spleen in aerobic exercise and resistance exercise groups was increased significantly (P< 0. 05). Conclusions Aerobic and resistance exercise delays age-related decline of immune functions in SAMP8 mice, and the expression of IL2/ IL2R upregulated by exercise may be its target.