The effect of temperature and time of injection molding for PET/PEN blend parison on the structure of bottle were studied. The microstructure, ester group exchanging rate and transparency of PET/PEN blend bottle were analyzed by using SEM, 1H-NMR, and light transmittance meter. The result showed that PET/PEN blend bottle’s transparency is higher when the injection molding process parameters are molded temperature 300 ℃ and period 180 s; water vapor transmission rate decreased by 19.1% compared to original PET bottle; moisture barrier property is better than PET bottle for edible oil.