The absorption, fluorescence emission and excitation spectra of algal suspension of Anabaena azotica Ley were measured. The fluorcscence spectra were measured at 293 K and 77 K. The wavelengths of excitation light were 430 nm, 475 nm, 615 nm and 650 nm. The spectra were compared after the algal suspensions were treated as below: (ⅰ) 0.04, 0.08, 0.12 0.16 and 0.20 μm DCMU; (ⅱ) 5, 10, 15, 20 and 25μm O-phcnanthroline; (ⅲ) 0.8 M Tris (pH 7); (ⅳ) 2, 5 and 8 mM hydroxylamine; (ⅴ) heating at 60°C for 4, 8, 12, 16 and 20 rain; (ⅵ) divalent, cations Mg~(++), Ca~(++) and Zn~(++). All these treatments affected the relative fluorescence intensity and the ratio of intensites of the peaks in the spectra. The data showed the possible route of energy transfer from earotenoids and phyeobilins to ehlorophylla a and the relation between pigments and protein. The absorption, fluorescence emission and excitation spectra of algal suspension of Anabaena azotica Ley were measured. The fluorcscence spectra were measured at 293 K and 77 K. The spectra of excitation light were 430 nm, 475 nm, 615 nm and 650 nm. were compared to the algal suspensions were treated as below: (i) 0.04, 0.08, 0.12 0.16 and 0.20 μm DCMU; (ii) 5, 10, 15, 20 and 25 μm O-phcnanthroline; (Ⅳ) divalent, cations Mg ~ (++), Ca ~ (+), (ⅳ) 2, 5 and 8 mM hydroxylamine; +) and Zn ~ (++). All these treatments affected the relative fluorescence intensity and the ratio of intensites of the peaks in the spectra. The data showed the possible route of energy transfer from earotenoids and phyeobilins to ehlorophylla a and the relation between pigments and protein.