The Department of Embryology, founded in 1995, is a part of Royan Institute’s Reproductive Biomedicine and Stem Cell Research Centers. During the preceding decade, a fundamental description of human and animal experimental studies has emerged in the field of embryology. The main focuses of this Department are: Increasing the quality of gametes and embryos, tudying molecular aspects of gamete maturation and embryo development, performing embryo co-culture with various types of somatic cells, tudying molecular aspects of gamete and embryo freezing, In vitro maturation of animal and human gametes, valuating molecular and cellular events of embryo implantation, Three-dimensional culture of cells to design an endometrial bio model, Three-dimensional culture of follicles in order to acquire good quality oocytes, Performing nuclear transfers, Performing animal cloning and transgenesis, Finding the best method for preserving gametes, ovarian, and testicular tissues.