Abstract: The percentages of glycerol level were determined for long time buck semen preservation and the highest post-thaw motility was observed using fifty-four ejaculates, collected twice in a week from the 3 mature Black Bengal Bucks (18 from each buck). Every 6 ejaculates from each buck were preserved in liquid nitrogen with different percentages of glycerol with tris-glucose-citric acid-egg yolk media by one-step dilution method. The motility was observed in fresh semen, two hours after chilling and 24 hours after freezing. In fresh semen there was no significant variation on sperm motility either between bucks or within the buck. Two hours after chilling the sperm motility was significantly higher (P<0.01) in 7% glycerol added diluents than that of 5 and 10% glycerol. Similar results were also observed following 24 hours after freezing (P<0.01), where the highest post-thaw motility was 52%. Therefore, 7% glycerol containing media appear to be suitable for preserving the Black Bengal Buck semen for future use.