Abstract: This study was designed to measure the effect of oxytocin on sperm morphology and prolongevity of motility of boar sperm kept at 18? C in diluent. Semen were taken from the same boar and diluted with citrate buffer. Diluted semen was containing 47x10 Sperm mLG . Two mLG aliquots of diluted semen were placed into a series of test tubes. The tubes were added with 20?LG of saline containing oxytocin to give a final concentrationof 5 i.u. oxytocin,mLG were kept as test group while the tubes added just only with 20?LG saline were kept as control group. The tubes were kept at 18?C and at 0, 3rd, 19th, 26th, 42nd, 49th and 56 th h three samples from each group were taken out for motility and morphology measurements. Percentages of zero time motility were taken as 100%. The mean time taken for 15 and 50% decrease in total motility for control and test groups (Mean?SD) were 41.0?1.0 and 35..0?4.8; 25.6?5.0 and 29.0?9.8 respectively. The mean time taken for 6% and 50% decrease in forward motility in control and oxytocin treated group were 33.7?3.0 and 33.4?7.0; 12.4?3.3 and 12.5?3.4 respectively. Neither of the differences in mean times taken for decreases in motilities, were statistically significant. The differences in sperm morphology were not also significant (p>0.05). Sperm motility and morphology are important parameters for fertilizing ability of sperm. These results show that addition of 5 i.u. oyxtocin has no effect on the mean time taken for certain decreases sperm motility or sperm morphology. Therefore oxytocin did not increase fertilizing ability of sperm in-vitro.