Herein we report that fibers of polybutadiene rubber (BR) with high morphological stability were made through combination of electrospinning and in-situ photo-crosslinking. This study revealed that (1) the formation of electrospun BR fibers was correlated with the overlap/entanglement of BR macromolecules in the spinning solutions; for the formation of uniform fibers without beads and/or beaded fibers, the concentration of spinning solution had to be higher than the "critical chain entanglement concentration (Ce)"; and (2) the in-situ photo-crosslinking was an effective method to considerably improve the morphological stability of electrospun BR fibers; upon prolonged storage under ambient condition or even upon immersion in tetrahydrofuran (a good solvent for BR), the crosslinked BR fibers well retained their morphology. It is envisioned that electrospun rubber fibers could be utilized for the development of innovative composites with substantially improved toughness and/or impact strength. (C) 2011 Elsevier B.V. All rights reserved.