Rodents provide an excellent experimental model to study human placental development. In this review, our aim was to explain major events that underlie the placental development in mammals in general, and specifically in rodent. Those events include trophoblast cell proliferation, decidual reaction and contact between the mesenchyme of the allantois with ectoplacental cone, all orchestrated by activation of a series of genes. We also aimed to compare molecular and genetic events of rodent and human placentation. Employing the rodent placenta development model will yield better understanding of these processes in other mammals, especially in humans.