Abstract: Objective To study reproductive toxicity of n-hexane gestational exposure in F1 Wista male rats.Methods Twenty-four pregnant Wistar rats were exposed to n-hexane at the concentrations of 0,360,1 800,and 9 000 mg/m³ via respiration for 4 hours a day from 1 to 20 gestation day.The male offspring(F1) rats were weighted every 3 days from postnatal day(PND) 9 and sacrificed at PND 69.Testis and epididymis organ coefficient,sperm survival ratio,sperm motility,sperm abnormality rate,and sperm density of the male F1 rats were observed.The testis tissues of the F1 male were consecutively sectioned and stained with hemotoxylin and eosin(HE) for microscopic observation of histopathological changes.Serum testosterone and malonaldehyde(MDA) in testis of the offspring rats were also measured.Results Compared with the control,body weight,testis organ coefficient,sperm survival ratio and motility,and serum testosterone were significantly declined and obvious dysplasia in testis was observed in the male rats with 9 000 mg/m³ n-hexane gestational exposure.No significant differences in MDA content of testicular tissue were observed among the rats with different concentrations of n-hexane gestational exposure.Conclusion Gestational exposure to high concentration of n-hexane could lead to obvious dysplasia of reproductive organ in male F1 rats and the dysplasia is not related to lipid peroxidation pathway.