SHEEP is substantial source of meat in many countries all over the world. But early embryonic death is a great problem negatively affects sheep production. This study was designed to investigate the effect of vitamin D3 administration before mating on reproductive performance of Rahmani ewes, referring to its impact on some biomarkers related to uterine receptivity during implantation period. Injection of single dose of vitamin D (300,000 IU/ ewe), resulted in less significant increment in serum pro-inflammatory cytokines (TNF-α and IL-6) and higher significant elevation in serum level of anti-inflammatory cytokines (IL-4 and IL-10), insulin like growth factor-1 (IGF-1), sterodogenic regulatory protein (StAR), macrophage inflammatory protein-1β (MIP-1β) and progesterone as compared to the ewes which did not receive vitamin D on 20th day after injection. Also, the treated group recorded an increased number of pregnant ewes upon pregnancy diagnosis on 40th day post-service and increased number of twins feti at delivery. On conclusion, vitamin D administration to ewes before mating has enhanced the reproductive performance of them through induction of some biochemical changes which would improve fertility and uterine embryos receptivity.