Based on argon laser of different wavelengths in visible light excited hemoglobin fluorescence spectra, it shows that there is one prominent fluorescence peak near 628 nm and the intensity increases with excitation light red shifting. The theoretical analysis indicates the hemoglobin fluorescence is mainly due to porphyrin fluorophores in it. In addition, it is found that the peak locations of 476.5 nm laser induced the fluorescence spectra hardly change with the sample concentration from 1% to 7%. The research indicated that the effects of laser are markedly different from that of normal light in the characteristics of low lever light-biotissue interaction.