Resumption of nuclear maturation and cytoplasmic changes occur during in vitro maturation. In vitro maturation of the egg provides a stage called Metaphase II (MII) that is required for in vitro fertilization. This study aimed to investigate the effect of replacing Follicle-Stimulating Hormone (FSH) with plant extract that 5 groups were used. The null group, which consisted only of oocytes, the control group, which used Fetal Bovine Serum (FBS) and FSH, the 3 experimental groups, in which different doses of Ajuga L. extract were substituted for FSH. Ajuga extract with appropriate dose increased the prevalence of Germinal Vesicle Degradation (GVBD), growth rate and maturity of immature mouse oocytes to MII stage.