Many synthetic scaffolds have been used as vascular substitutes for clinical use. However, many of these scaffolds may not show suitable properties when they are exposed to physiologic vascular environments, and they may fail eventually because of some unexpected conditions. Electrospinning technology offers the potential for controlling the composition, structure, and mechanical properties of scaffolds. In this study, a tubular scaffold (inner diameter = 4.5 mm) composed of a polylactide (PLA) fiber outside layer and a silk fibroin (SF)-gelatin fiber inner layer (PLA/SF-gelatin) was fabricated by electrospinning. The morphological, biomechanical, and biological properties of the composite scaffold were examined. The PLA/SF-gelatin composite tubular scaffold possessed a porous Structure; the porosity of the scaffold reached 82 +/- 2%, The composite scaffold achieved the appropriate breaking strength (1.28 +/- 0.21 MPa) and adequate pliability (elasticity LIP to 41.11 +/- 2.17% strain) and possessed a fine suture retention strength (1.07 +/- 0.07 N). The burst pressure of the composite scaffold was 111.4 +/- 2.6 kPa, which was much higher than the native vessels. A mitochondrial metabolic assay and scanning electron microscopy observations indicated that both 3T3 mouse fibroblasts and human umbilical vein endothelial cells grew and proliferated well on the composite scaffold in vitro after they Were Cultured for some days. The PLA/SF-gelatin composite tubular scaffolds presented appropriate characteristics to be considered as candidate scaffolds for blood vessel tissue engineering. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 2675-2682, 2009