Recently, electrically conductive biomaterial scaffolds have shown great potential in tissue regeneration. Herein, we reported an electrically conductive polyaniline (PANI) coated poly(epsilon-caprolactone) (PCL) electrospun micron -fiber scaffold for the enhanced attachment and proliferation of human umbilical vein endothelial cells (HUVECs) under electrical stimulation conditions. After the 02 plasma treatment toward PCL electrospun fiber, PANI could be polymerized onto their surfaces successfully. The obtained PANI-PCL fibers were characterized by SEM observations, FT-IR spectra, XPS analysis, and water contact angle measurement. The mechanical tests indicated that the fibers could satisfy the practical vascular scaffold requirements. The conductivity of the PANI-PCL fibers was 6.71 x 10(-3) S/cm which could provide a conductive in-vitro platform to study the effect of electrical stimulation on HUVECs proliferation. When PANI-coated PCL fibers were compared with PCL fibers, HUVECs exhibited highly enhanced adhesion and viability, especially under electrical stimulation (ES) of 200, 300, and 400 mV/cm. Proliferation of HUVECs on PANI-PCL fibers was strongly dependent on electrical stimulation intensity. The results showed new insights into conductive scaffolds for vascular tissue engineering. (C) 2016 Published by Elsevier B.V.