This book was designed to assess the effect of different concentrations of L-carnitine and Co enzyme Q10 (CoQ10) on the outcome of in vitro human sperm activation and to find out if there are any side effects of L-carnitine and CoQ10 on the sperm deoxyribonucleic acid (DNA) integrity using DNA fragmentation index test. This study was conducted on samples of semen of infertile and fertile men were collected randomly. The mean age of the men was (32.034 ± 0.57) years with mean duration of infertility (4.644 ± 0.25) years. The First Chapter contains an introduction on fertility and fertility factors, semen analysis, as well as a detailed explanation of all the subjects for the L. carnitine and the Co Q10. In addition to the detailed explanation of the DNA fragmentation. Chapter Two contains tools, equipments and chemicals used in the study listed in tables, also contains an experimental design for the study. In Chapter Three we can see the results of the study reinforced by figures and tables for each type before and after activation. In the Fourth Chapter the study results was discussed with carefully analyzing and comparing them with the results of other similar studies.