Pleistocene is regarded the last series of the modern life that includes four of five series. This series is regarding the fourth one. Most scholars now days consider the modern life as an extension of Pleistocene. Others exclude it as a special period naming it Holocene. Pleistocene has witnessed many geological, geographical and natural changes that extended up till the present day. In this series many types of animals and plants have appeared clearly that some types of them still exist due to the convenant environmental factors. More over this series which can be traced back to (2) million years ago. as estimated by scholars also witnessed many changes as far as human physical and intellectual activities are concerned. More remarkably in this series glacier formation has occured in the northern part of the globe. This series was long enough to be divided into four glacial series: Gunz, Mindle, Riss and Wurm. It is characterized by severe coolness. It was punctuated by many inter-glacial Series in which the glacier thawed and heat temperature rose. Consequently these inter-glacial series had direct effect on the climate and on the flora and funa. A similar effect has been left on human life according to the environmental changes that accompanied those series.