The objective of this M.sc dissertation is about Sistani cattle as one of the most important cattle in the country of Iran. Evaluation of quantitative and molecular genetic approach is required for designing of any breeding strategy in this breed. This dissertation tried to review the application of Biotechnological methods in animal science with emphasis on concepts of candidate gene and DNA marker technology. Growth hormone and its receptor gene polymorphism provide useful information for estimation of breeding value for growth trait and could be appreciable for overcome to some of the limitation of the conventional selection methods.