In this experiment, pure PBSU fibers, PBSU/12.5% beta-CaSiO3, and PBSU/25% beta-CaSiO3 composite fibers were fabricated by electrospinning. In order to investigate the effects of surface modification of beta-CaSiO3 on composite fibers, beta-CaSiO3 nanowires were surface esterified using dodecyl alcohol. SEM micrographs showed that composite materials with modified beta-CaSiO3 have homogeneous fibrous structures similar as that of pure PBSU fibers, while the fibers containing unmodified beta-CaSiO3 were inhomogeneous and much larger in diameter, and also junctions where beta-CaSiO3 agglomerated could be found. Mechanical testing showed that with the addition of unmodified beta-CaSiO3 into PBSU matrix, the tensile strength of fibrous materials decreased obviously, and the decrease degree increased with increased beta-CaSiO3 content. However, the tensile stresses of composite materials after surface modification Of beta-CaSiO3 turned back and increased about 40% compared to those containing unmodified beta-CaSiO3. All of these results suggested surface modification of beta-CaSiO3 was an effective approach to obtain composite fibrous materials with better morphologies and enhanced mechanical properties, and this method is supposed to be feasible in other fibrous material systems. (C) 2009 Elsevier B.V. All rights reserved.