Surface chemical compositions of PCL mats modified by different LBL coatings were analyzed by XPS and the results were shown in Fig.2B and C. Signals of nitrogen, sulfur and fluorine elements on the wide scan spectrums confirmed the present of PEI, heparin and DEX, respectively. In the curve fitting of C1s high resolution spectrum of (PEI/HEP)x,C-C/C-H,C-N/C-NH2,C-O/C-OH and COOH were found at 284.8,285.6,286.4 and 288.5 eV,respectively.