New technique is developed to synthesize graphene film on flexible substrate for strain sensing applications. A flexible graphene/Poly-ethylene Terephthalate (PET) strain sensor based on graphene piezoresistivity is produced by a new simple low cost technique. Graphene oxide film on PET substrate is reduced and patterned simultaneously using 2 Watt CO 2 LASER beam. The synthesized graphene film is characterized by XRD, FT-IR, SEM, and Raman techniques. Commercial strain gauges are used to predict experimentally the gauge factor (GF) of the graphene film at different values of applied strain. The stability of the graphene film and its GF are studied at different operating temperatures. The fabricated sensor showed high GF of 78 with great linearity and stability up to 60 oC.