This study investigated the influence of sodium bicarbonate (NaHCO 3 ) and progesterone on acrosome reaction and proportion of polyunsaturated fatty acid (PUFA) composition boar sperm. The sperm were diluted with semen extender and incubated with NaHCO 3 and progesterone at 38℃, 5% CO 2 for 6 h. Plasma membrane integrity and acrosome reaction were analyzed using SYBR14/propidium iodide (PI) and FITC-PNA/PI doubling staining method, and proportion of PUFA was analyzed using gas chromatography. In results, Plasma membrane integrity was significantly decreased in 50 mM NaHCO 3 group and acrosome reaction was significantly increased by over the 100 mM NaHCO 3 group compared to control group (p < 0.05). In addition, progesterone significantly increased decreased plasma membrane integrity at 100 mM progesterone and acrosome reaction at over the 5.0 μM progesterone (p < 0.05), but there was no difference among the 5.0 to 100 μM groups. PUFAs were significantly decreased in 100 mM NaHCO 3 and 50 μM progesterone treatments compared to control group. In summary NaHCO 3 and progesterone induce acrosome reaction and reduce PUFA composition in boar sperm, therefore, the results maybe help to understand basically knowledge for the acrosome reaction and PUFA composition in boar sperm.