tThe aim of the present study was to evaluate the effects of dietary n-6:n-3 fatty acid(FA) ratio and vitamin E on the semen quality, FA composition and antioxidant status ofboars. Forty-eight Landrace boars were randomly distributed in a 3 × 2 factorial design withthree n-6:n-3 FA ratios (14.4, 6.6 and 2.2) by the inclusion of three oil sources (soybean,fish/soybean, fish) and two vitamin E levels (200 and 400 mg/kg). During the 8 weeks oftreatment, semen parameters were evaluated. Serum, sperm and seminal plasma sampleswere taken at 0 and 8 weeks to monitor the FA composition and antioxidant status. Resultsshowed that the 6.6 and 2.2 dietary ratios very effectively increased docosahexaenoic acid(DHA) and n-3 polyunsaturated fatty acid (PUFA) and decreased docosapentaenoic acid(DPA) and n-6:n-3 ratio in spermatozoa. The 6.6 dietary ratio contributed to a greater pro-gressive sperm motility (P < 0.05) than the 14.4 and 2.2 dietary ratio, and this ratio alsoenhanced the superoxide dismutase (SOD) and total antioxidant capacity (TAC) (P < 0.05)in seminal plasma more significantly than the other two ratios at week 8. Comparedwith 200 mg/kg supplementation of vitamin E, 400 mg/kg supplementation of vitamin Eincreased the progressive sperm motility, SOD of sperm, TAC and SOD of seminal plasmaand serum, and decreased sperm malondialdehyde (MDA) (P < 0.05). In conclusion, the 6.6dietary ratio and 400 mg/kg vitamin E supplementation improve progressive sperm motilityby modifying the sperm FA composition and antioxidant status