HexafluorobisA polyethersulfone-cardo polyethersulfone, random and block copolymers with different segment lengths were synthesized by a reaction of 4,4’-(hexafluoroisopropylidene)diphenol and 3,3’-bis(4-hydroxyphenyl)-1-isobenzopyrrolidone with bis(4-chlorophenyl) sulfone. Their NOE-suppressed quantitative C-13-NMR spectra were recorded on a 400 MHz NMR spectrometer. The C-13-NMR signals of tertiary carbon atom and quaternary carbon atom, on the benzene ring adjacent to sulfone group, appeared to be sensitive to sequence variation. Degrees of randomness of the copolyarylethersulfone synthesized were 0.96, closing to 1, and 0.39, as well as 0.55, far smaller than 1, indicating random distribution and regular distribution of the comonomers, respectively. The number average sequence lengths, calculated by C-13-NMR spectra, were shorter than expected, due to the transetherification reaction.