The aim of the research was to determine whether and how the two doses of laser irradiation energy (3.96 and 6.12 J /cm2) can improve the quality characteristics of ram sperm after freeze-thaw process. In this regard semen straws were thawed in water bath at 39oC for 120 seconds. After thawing, semen was divided into three samples: one representing control and the other two were exposed to He-Ne laser irradiation at two different doses of energy (3.96 and 6.12 J /cm2) and mitochondrial activity, cell viability (by flow cytometry), motility and function of plasma membrane integrity test (HOST) were analyzed. He-Ne laser action on thawed ram semen leads to an improvement of motility, viability, mitochondrial function and functional integrity of the membrane for the dose of 6.12 J /cm2, in contrast to the dose of 3.96 J /cm2 which decreases the quality of semen parameters relative to the control sample.