Asphalt an important construction material is a natural constituent of most petroleum. Oxidation of asphalt when in service, due to atmospheric oxygen and ultra violet exposure, is a process that leads to embrittlement, loss of ductility and adhesion. The durability of asphalt products depends also on the environmental variations especially in the areas where high temperature differences are recorded. High temperature stiffness and low temperature flexibility are important properties of asphalt products. This article shows how some properties of asphalt can be improved by using some additives (modifiers). Studies done arrived to the conclusion that such additives must have: a certain average molecular weight, compatibility, a solubility parameter close to those of asphalt main components, to be in an amount to lead by mixing with asphalt to lower content of air voids. From these points of view, polymeric materials seem to be the most promising asphalt modifiers. This review provides some data related to the effects on asphalt of polyolefins, thermoplastic elastomers, and some recycled polymers.