An Arg-Gly-Asp (RGD) peptide-immobilized electrospun matrix of polyurethane (PU) was developed for the enhanced affinity of endothelial cells (EC). The novel PU matrix was fabricated as a vascular shape using the electrospinning technique. Then, poly(ethylene glycol) (PEG) was immobilized on the porous PU matrix as a spacer, followed by conjugating RGD peptide to the amino end group of the PEG chain. In the proliferation test of human umbilical vein endothelial cells (HUVEC) on the modified PU matrix, the RGD-immobilized porous matrix showed enhanced viability of HUVEC as compared with an unmodified surface, demonstrating that the presence of RGD peptide promoted HUVEC proliferation. In addition, the RGD-immobilized PU porous matrix revealed higher cell viability than the RGD-immobilized PU film because of the porous structure with higher surface area, indicating an advantageous property of the porous matrix for HUVEC proliferation.