Nowadays modifying specifications of bitumen propounded in form of a new subject in producing hot asphalt in the world.In Iran modifying of biumen can increase operative age of asphalt up to a noticeable level. This research wants to find modified bitumen producing mechanisms with polymers which have been produced in our country and then act a limit consideration about modified bitumens.A strong shear machine with controled equipment was designed and made for producing modified bitumens. This machine can remit the obtained product to the reliable adaptation under chronological coditione and proposed temperatur in each exam.Results from experiments and studies showed that polymer APP has improved such traits as penetration, softening point, viscosity, frass breaking point and ductility to an acceptable degree. Calculations of thermal sensitivity has put the improved tar at this research in the group of tars with little thermal sensitivity.