Anti oxidant effect of green tea extract on 47 cryo preserved human semen samples were studied. Each sample was divided into two- one with green tea extract and the second without green tea extract. Percentage of motility, viability and DNA fragmentation were examined. While comparing the study results of control vs. green tea extract samples, the mean value of percentage of motility in control group was 51.2 with standard deviation of 10.18 vs. 53.03±10.40 in green tea extract group. The percentage of viability and standard deviation in control yielded 59.63±10.13 and it was 61.38±10.29 in green tea extract group. The mean and standard deviation in percentage of DNA fragmentation was 73.49±5.24 in control and it was 67.04±5.02 in green tea extract group. The students paired t-test results showed statistically significant increase in percentage of motility and viability and reduction of DNA fragmentation in green tea extract group compared to control with p-value less than 0.05. Green tea is an effective anti oxidant and it reduces the DNA fragmentation and it increases the motility and viability of sperms, thus it can be use as an effective anti oxidant in cryo preservation of human sperms.