Blends of polyethylene terphalet (PET) with polylactic acid (PLA) were investigated to determine the influence of the addition of PET on mechanical and optical properties. The compositions were prepared in wt (20/80), (50/50), (80/20). Mechanical properties like tear strength, and optical properties like colors and transparency were also reported. Polyethylene terphaletee decrease the tear strength when adding PET and Impact strength of PLA was increased when adding PET when tested in the machine directions. Optical property such as colors was increased and the value of transparency was decreased as the loading of PET increased.