A photo-crosslinkable ployfluorene with oxetane group was synthesized and characterized by NMR,elemental analysis,etc.It was evidenced that the introduction of photocrosslinkable oxetane group has very little effect on the blue-light-emission of polyfluorene.Insoluble polyfluorene films were obtained by crosslinking with the addition of the triarylsulfonium salt photoinitiator under UV irriation.It was revealed that the optoelectronic properties of crosslingked polyfluorene displayed little change compared with uncrosslinked polyfluorenes.