Abstract: The π electron molecular orbital energy level and electron spectra of some unsymmetrical bisazo derivatives of chromotropic acid containing halogen group were studied by HMO method.Results of calculations show that the wavelength of the maximum absorptive peak differs from experimental value by 8nm and the substituting position of electrophilic group agrees well with experimental value.We also discussed the red shift of electron spectra and the substituting position of e:lectrophilic group from these results.