As an alternative compound of bisphenol A (BPA), bisphenol B (BPB) was widely used in plastic materials. The potential actions of BPB on the function of Leydig cells through the regulation of H3K27me3 and H3K9me3 remains unclear. Our goal was to assess how BPB influences Leydig cell function via histone modifications mediated by H3K27me3 and H3K9me3. Male 56-day-old Sprague-Dawley rats were given with 0, 50, 100, and 200 mg/kg/day of BPB by the oral administration for 14 days to study the impact of BPB on the function of Leydig cells in rats. The findings indicated that BPB significantly reduced the serum testosterone levels at the dose of 100 mg/kg and 200 mg/kg and follicle-stimulating hormone levels at the doses of 50, 100, and 200 mg/kg, while increasing estradiol levels at the dose of 200 mg/kg. BPB did not alter the numbers of CYP11A1