Abstract: Nitrogen ion implantation of LTI-Carbon and its hemocompatibility were investigated. The implanted energy was 30～160keV and dose of nitrogen ions was and 8×10¹⁶～6×10¹⁷ ions/cm² respectively. The structure and composition of samples were analysed by Rutherford backscattering spectroscopy （RBS）, X-ray diffraction （XRD） and Raman spectra. Platelet adhesions of LTI-carbon before and after implantation were also investigated.The results show that after nitrogen ion implantation, less platelets are adhered to the surface. Moreover, there are less conglomeration and transfiguration. PIII-treated surfaces adsorb more HSA, but less HFG than untreated LTI-carbon, which show that after PIII treatment the samples have better anticoagulation properties than LTI-carbon .