In the study, magnetic poly(hydroxyethylmethacrylate-N-methacryloyl-(L)-histidine) (mPHEMAH) nanoparticles were prepared by miniemulsion polymerisation using N-methacryloyl-(L)-histidinemethylester as basic monomer. The specific surface area of the magnetic nanoparticles was found to be 1050 m(2)/g. Maximum Protein C adsorption capacites of the Ni(II), Cu(II) and Zn(II) ions chelated magnetic poly(hydroxyethyl methacrylate-N-methacryloyl-(L)-histidine) nanoparticles were calculated as 589.22, 436.33 and 388.15 mg/g nanoparticles, respectively. This work was focused on the purity of the Protein C by sodium dodecyl sulphate polyacrylamide gel electrophoresis yielding a satisfactory result of 92% purity. The reusabilitys of the Ni(II)-mPHEMAH, Cu(II)-mPHEMAH and Zn(II)-mPHEMAH nanoparticles were approximately 93.5%, 94% and 95% respectively.