A novel magnetic nanocarrier was strategically designed and successfully prepared. Photosensitizer 2, 7,12, 18-tetramethyl-3, 8-di-(1-propoxyethyl)-13, 17-bis-( 3-hydroxypropyl ) porphyrin ( PHPP ) wasencapsulated into polylactic acid (PLA)-coated Fe3O4nanoparticles. The diameter of nanocarrier is 30-50 nm by transmission electron micrograph ( TEM ). The encapsulation efficiency of photosensitizer is 27.98% calculated from UV-vis absorption spectra. The nanocarrier shows obvious photocytotoxic activity to Hela299 tumor cells in vitro.