The synthesis and characterization of PEG-like macromolecular structures on Nitinol surface from tri (ethylene glycol) dimethyl-ether under ECR-cold-plasma conditions were discussed. It was demonstrated that based on high-resolution ESCA, ATR-FTIR and contact angle investigations, the deposited PEG-like layers are composed mainly of -CH2-CH2-O- linkages. These structures have a relatively low contact angle. Compared to the unmodified surfaces, the plasma-treated Nitinol surfaces are more hydrophilic. Plasma enhanced coatings of PEG-like layers can prevent Ni ion from releasing, thereby improving the biocompatibility of Nitinol.