The characterization and gas permeation properties of ultraviolet (UV)-cured fluorine-containing telechelic polyimide membranes and end-capped with a crosslinker with acryloyl groups were investigated. Membrane formation property was improved by the addition of crosslinker by using UV irradiation. The densities of UV-cured membranes were almost similar to each other, and high gel fraction was shown on the UV-cured membranes. This result suggests that the crosslinker promotes crosslink reaction at the polymer chain ends and does not induce appreciable membrane densification. Furthermore, the gas permeability of the UV-cured membranes was higher than that of the membrane without the crosslinker. The higher gas permeability is due to the new crosslink structure formed at the polymer chain ends, which was promoted by the crosslinker after UV irradiation, but did not induce appreciable membrane densification. The use of a BEI crosslinker in the telechelic polyimide membranes promoted the crosslink reaction and increased the H-2 selectivity because H-2 permeability was not sensibly affected by the crosslink reaction. POLYM. ENG. SCI., 54:1089-1099, 2014. (c) 2013 Society of Plastics Engineers