In this study, polyamide 12 film was casted by twin screw extruder and followed by bi-axially stretching with various ratios. In the first part, the thermal properties and crystallization kinetics were analyzed by measuring the enthalpy in the adiabatic or isothermal process by using differential scanning calorimetry (DSC). Furthermore, the properties of BOPA 12 film were analyzed including stress, optical properties, micro structure, water vapor transmission rate (WVTR) and oxygen transmission rate (OTR).