The interaction of glucose oxidase (GOD) and four photosensitizers, ZnpcS4,ZnPc(NHCH2COOH)4, CIAIPcS, and porphyrine-like, were monitored by capillaryelectrophoresis. GOD, its degenerated products and photosensitizers were simultaneouslyseparated in a buffer of 300 mmol/L borate at PH 8.5 on a commercial CE instrument. Bycomparison of the electropherograms of GOD as well as the mixture of GOD and photosensitizerswithout/with irradiation of different time, it was found that photosensitized oxidationsbetween GOD and different photosensitizers have different reaction mechanisms and kinetics.