A novel water-soluble and polymerizable photosensitizer, zinc tetra(N-carbonylacrylic)aminophthalocyanine (Zn-MPc), was synthesized by the ornament of zinc tetraaminophthalocyanine (Zn-APc) with maleic anhydride and characterized by 1 H NMR, FT-IR, and MALDI-TOF mass spectra. The photoactivity of Zn-MPc was determined by tracking the degradation of 1,3-diphenylisobenzofuran (DPBF). The results indicated that Zn-MPc is an efficient photosensitizer and has a high photostability. The apparent rate constant, k a , of DPBF photodegradation increased with the increase of the Zn-MPc concentration or light intensity, but declined with the increase of the initial concentration of DPBF. Furthermore, the kinetics equation was deduced as Rd=1.12×10 −5 [DPBF] 0.51 [Zn-MPc] 0.54 E 1.35 . The results in this work provide a basis for the further development of more desirable phtotosensitizers and their applications in photodynamic therapy (PDT) of cancer.