This work investigated the performance of butane decomposition in a dielectric barrier discharge (DBD) plasma reactor at room temperature. Effects of input power, type of packing material, gas composition and initial butane concentration on the decomposition and the distribution of byproducts were examined and discussed. Even though glass wool (GW) packing material loaded with TiO 2 or graphene oxide (GO) photocatalyst exhibited nearly the same butane decomposition efficiency with bare GW, the loading of TiO 2 or GO improved the formation of CO 2 rather than CO as a byproduct. The butane decomposition efficiency obtained in the presence of a small amount of O 2 as a feed gas constituent is much higher than that in the presence of the same amount of argon or helium. Byproducts formed in the presence of O 2 were oxidized compounds such as CO, CO 2 , acetone and acetaldehyde, whereas acetylene and methane were produced in the presence of argon or helium. The decomposition efficiency decreased with increasing the initial butane concentration. The addition of O 2 avoided the formation of acetylene and methane with enhanced production of CO 2 and CO. From emission spectra taken during plasma discharge, various reactive species including radicals, ions and excited molecules were identified, depending on the gas composition.