In this study, we show that the plasma-initiated polymerization (PIP) can be carried out at ambient pressure using the dielectric barrier discharge (DBD) technology. The structure of styrene-maleic anhydride copolymer (SMA) is analyzed by 1H and 13C-NMR. The effects of initiation time, gas flow rate, post-polymerization time, and temperature on yield are also discussed. The results show that SMA exhibits a dominant alternating structure. The yield of SMA increases with the increase of initiation time and polymerization temperature, remains unchanged with the increase of flow rate, and decreases rapidly with the increase of St-MAH molar ratio. The PIP in this experiment is shown to follow the free-radical polymerization mechanism and the process of the polymerization is also discussed. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012