In this paper, 2’,7’-dihalofluorescein (DFF, DCF and DBF) were synthesized by the Diels-Alder reaction of 4-haloresorcinol with phthailc anhydride in the persence of methanesulfonic acid as catalyzer, and their structures were characterized. The pH titrations indicate that the dependences of fluorescent properties for these compounds on pH were extremely sensitive in the absorption spectra and the fluorescence spectra. The absorption intensities at 490, 502 and 505 nm, and the fluorescent intensities at 517, 526 and 530 nm in DFF, DCF and DBF increased with pH increasing, respectively. When the pH > 10, the absorption intensities and fluorescent intensities slightly decreased and then kept constant. The result shows that the thermodynamic pKa values and fluorescence quantum yields of DFF, DCF and DBF are 4.7, 5.1 and 6.6, and 0.97, 0.94 and 0.67, respectively. The photodegradation experiment indicated that photostabilities were DFF﹥DCF﹥FL﹥DBF in order.