Membranes made of hybrid poly(lactide-co-glycolide)/chitosan fibers (H-PLGA/chitosan) and core/shell structured PLGA/chitosan fibers (C-PLGA/chitosan) were produced by coelectrospinning and coaxial electrospinning, respectively. The morphology, mechanical properties, water uptakes of the electrospun fibrous membranes were characterized, and the cytocompatibility Of human embryo skill fibroblasts (hESFs) was investigated in comparison with each other as well as with the electrospun PLGA and chitosan membranes. Results of transmission electron microscope and X-ray photoelectron spectroscopy confirmed the core/shell structure of the C-PLGA/chitosan fiber. Because of the introduction of chitosan, both H-PLGA/chitosan and C-PLGA/chitosan membranes showed significantly higher water uptakes than that of PLGA but there was no significant difference between those of C-PLGA/chitosan and chitosan membranes. In dry state, the C-PLGA/chitosan membranes exhibited extremely higher Young's moduli (178.7 +/- 50.4 MPa) and strength (2.73 +/- 0.30 MPa) than those of H-PLGA/chitosan membranes (40.48 +/- 4.07, 1.44 +/- 0.12 MPa), respectively, but the values in wet state went down sharply because of the large amount (about 91%) of chitosan as the shell. Both H-PLGA/chitosan and C-PLGA/chitosan membranes showed better cytocompatibility than the PLGA membrane in adhesion, viability assays as well as morphology observation. The obtained composite H- or C-PLGA/chitosan membranes Would be potentially applied in wound dressings or skill tissue engineering. (C) 2009 Wiley Periodicals, Inc. J Biomed Mater Res 92A: 563-574, 2010