Regarding its generation source bitumen can be classified intothree categories: natural, petroleum asphalts, coal tar pitches: A- Natural bitumens or native asphalts are a class of bitumenswhich have been naturally produced due to climate conditions in the course of time,and are used without the need to be processed in distillation ways; they arevery varied regarding their composition and properties.  B- Coal tar Pitches are hard black substances which are formed asthe result of coal tar distillation. Their new broken surface is shiny and whenthey are heated they , along with fast decrease in viscosity, melt and theirmelting point depends on the production process.  C- Petroleum Asphalts are the bitumens which are derived frompetroleum .These are solid and semi solid bitumens which are directlyproduced through distillation from petroleum or by additional operations such as airblowing. Compared with the other types, they are more commonly used and have moreapplications.Â