Abstract: In this time, for treatment of sterility high technology is available. Even one spermatozoid or one head could be fertile oocyte. When we study aging for spermatozoid, this is question, how does spermatozoid grow old and die? After spermatogenesis, how long time does spermatozoids remain at 4°C? For this experiment 10 Lori rams in similar age were selected randomaizely. All of them killed and cut off deferent ductulus (between epydidymis and ampulla). Spermatozoids was extracted and place in epindorf. Solution 1 million mL-1 prepared and stored at +4°C. Motility was 93% and after 13 h, motility significantly was decreased. Percent of sperm head was low (2%) but in many samples, percent of tail was observed 5%. Majority of spermatozoa remained normal and not change significantly at +4 degree centigrade up to six month. Proportion of coiled spermatozoa was very low. Cell membrane in ram spermatozoa very specific and resistance to cold shock.