Gallic acid substituted zinc phthalocyanine (GA-ZnPC) was synthesized from 4-hydroxybenzaldehyde and 3,4,5-trimethoxybenzoyl chloride. Its structure and spectral characteristics were characterized utilizing FTIR, 1HNMR, MALDI-TOFMS, UV-Vis spectra, and Fluorescence Spectroscopy．The results reveal that GA-ZnPc is soluble in multiple organic solvents. When the concentration of GA-ZnPc is 2×10-6～1.0×10-5 mol/L, it exists in the monomeric form in DMF with Q-band maximum absorption peak appearing at 692 nm. Spectral titration was performed with GA-ZnPC DMF solution at a concentration of 2×10-6 mol/L, and the results confirm that GA-ZnPc maintains its monomer form, possessing apparent alkali-sensitive fluorescence characteristics owing to the intramolecular electron transfer enhanced by phenol to phenate transition．