This study aimed to improve the barrier property of poly (propylene carbonate) (PPC). In this study, the SiOx layer was deposited on the PPC film surface by plasma enhanced chemical vapor deposition (PECVD) technique, and the evaluation on oxygen barrier property was used as the research target. The SiOx layer was successfully deposited on PPC film surface by PECVD technique, and the optimum process was 150 watts of power, 6 mL/min∶12 mL/min of HMDSO/O2, and 60 min of deposition time, and the oxygen barrier of PPC was enhanced observably by deposition of SiOx layer. The barrier property of PPC against oxygen, vapor and UV was improved by deposition of SiOx layer on its surface by PECVD technique and its toughness was retained.