Increasing urbanization and industrialization have contributed for increased plastic generation in Ethiopia. Unsafe disposal of waste plastic is a serious environmental problem. The application of waste plastics to modify bitumen for asphalting of roads can possibly minimize those problems since the polymer modified roads showed superior resistance to environmental stresses in countries if the technology has been implemented. PET plastic bottle is generated daily in Bahir Dar city and released as a waste after usage. Releasing them to the environment, they pose negative impact to the environment. So to overcome such problem reducing solid disposal there is an idea to utilize waste PET bottle plastic in bitumen modification for asphalt road construction pavement using wet process technology. The conditions used were: plastic content (0%, 2%, 3.5%, 5%, 6.5%, and 8%)by mass of bitumen, plain bitumen content in testing of its maximum stability (4.5%, 5%,, 5.5%, and 6.5%) by mass of aggregates. The maximum stability of plain bitumen was obtained at 5.2% and by conducting the test at this bitumen plastic mix content, it was obtained maximum stability at 3.5% of plastic content. The modification and aggregate mix average temperature was 180 0C. This result showed that strength of the modified bitumen is improved which shows highly resistance against rutting and permanent deformation