Absorption and fluorescence spectra of the chromoprotein changed during the ApcD of core subunit from Anabaena sp. PCC 7120 bound PCB with reconstitution in E. coli, the λ_max of absorption and fluorescence spectra were 605 nm and 633 nm before purification, while the λ_max of absorption and fluorescence spectra were 650 nm and 665 nm after purification. To study the phenomenon above, eight mutants were constructed. It is indicated with reconstitution in E. coli that: the mutant ApcD (Y88I) had one more absorbance and fluorescence peaks after purification , the λ_max of absorption and fluorescence spectra were 668 nm and 690 nm. The spectra of ApcD (W59Q), ApcD (Y73A), ApcD (W87E) had no change during the purification. The absorption spectra of ApcD (M126S), ApcD (Y116S), ApcD (M160T) had no change during the purification, but the fluorescence spectra had red shifts by 5 nm, 7 nm and 10 nm after purification, respectively. The λ_max of absorption and fluorescence spectra of ApcD (M115I) had changed from 605 nm and 633 nm to 638 nm and 655 nm. Under acidic urea conditions, those chromoproteins had maximal absorption at 662 nm, indicating that they had PCB chromophore. Under the study of CD spectra of PCB-ApcD, PCB-ApcD (Y116S) and PCB-ApcD (M160T), the two mutants influenced the conformation of chromophore which bound with apoprotein, but not affected the secondary structure of the reconstitution proteins.