Abstract: This work is to investigate the protective effect and mechanism of sulfated polysaccharide (SP) on HPM-induced GC-2 cell injury. The mouse spermatogenic GC-2 cells were divided into drug group, drug control group, radiation group and control group. All cells were exposed S-band HPM with an average power density of 30 mW/ cm² for 15 min. The drug group and the drug control group were added to the SP concentration of 25 μg/ ml at 24 h before microwave irradiation. After exposure, the ROS content, expression of apoptosis-related proteins Caspase3, p53, Bax and Bcl-2, and p-38MAPK and p-JNK1/2 in MAPK signaling pathway of cellular oxidative stress were detected immediately. Cell viability was measured at 1 h, 3 h, 6 h, 12 h, and 24 h after exposure. Compared with the normal group, the proliferation activity of the irradiated group at 6h was significantly decreased, and the immediate ROS content of the cells and the expression of Caspase 3, p53, Bax, p-38MAPK and p-JNK1/2 were significantly increased and the expression of Bcl-2 significantly decreased; the drug group and drug control group, compared with the radiation group, the immediate ROS content of cells and the expression of Caspase 3, p53, Bax, p-38MAPK and p-JNK1/2 were significantly decreased and the expression of bcl-2 significantly increased. The results showed that S-HPM radiation could induce oxidative stress damage to GC-2 cells and prophylactic administration of SP could protect HPM radiation damage through antioxidant mechanism.