Objective To study the differences and mechanisms of damage to the reproductive organs of male rats by single and compound exposure to microwaves at 2.856 and 9.375 GHz.Methods A total of 40 male Wistar rats were randomly divided into sham group,S10 group,X10 group and SX5 group.Microwavesat 2.856 and 9.375 GHz were used to expose the rats for 6 min in the S10 and X10 groups with an average power density of 10 mW/cm2,respectively.The SX5 group was sequentiallyexposed to 2.856 and 9.375 GHz microwaves with an average power density of 5 mW/cm2 for 6 min.At 1 and 7 d after exposure,the sperm viability and serum sex hormones were detected by light microscopy and electron microscopy,and testicular tissue structure and oxidative stress and energy metabolism levels were examined.Results The sperm viability,testosterone(T),follicle stimulating hormone(FSH),and inhibin B(INHB)decreased in the S10 and X10 groups at 1 and 7 d after exposure(P＜0.01),and in the SX5 group at 7 d after exposure(P＜0.05).The LH decreased in all the exposure groups at 1 d after exposure(P＜0.01),and increased in the S10 and X10 groups at 7 d after exposure(P＜0.05).The spermatogenic epithelium of testicular tissue was lax,spermatogenic cells were edematous and vacuolated,chromatin condensed and shifted side by side,and the damage was significant in the S10 and X10 groups as compared with the SX5 group.The superoxide dismutase(SOD)activity in testis tissue decreased and malondialdehyde(MDA)content increased at 1 and 7 d after exposure in the S10 group(P＜0.01).In the X10 group,the SOD decreased at 1 d after exposure(P＜0.01).The lactate dehydrogenase(LDH)and succinate dehydrogenase(SDH)activity and adenosine triphosphate(ATP)content in testis tissue decreased at 1 and 7 d after exposure in the S10 and X10 groups(P＜0.05).In the SX5 group,the LDH and SDH decreased at 1 d after exposure(P＜0.05).Conclusion Single and combined exposure to S-band and X-band microwaves can cause damage to male reproductive organs.The S-band causes damage more significantly than that of X-band.Single-frequency microwave high-intensity exposure causes damage more significantly than that of multi-frequency microwave prolonged combined exposure.The damage is closely related to oxidative stress and energy metabolism.