The geometries of bis(4-dimethylaminophenyl)squaraine and its N and C-2 derivatives have been obtained by AMl and Gaussian 92.The relationship between their photosensitivties and geometries has been studied respectively. The linear relationships between oxidation Potential (EOX) of compounds 1-6 and their HOMO energy (EH), between the Photosensitivity (lgE0.5) of compound 1-5 and ΔET- X (the difference of the oxidation potential of charge-transporting material (CTM) and charge-generating material (CGM)), between lgE0.5 and ΔET-G (the difference of the HOMO energy of CGM and CTM) have been studied respectively by the least square fitting method. The result indicates that Eox and EH exhibit certain linearity (r=0.883), the correlation coefficient of lgE0.5 and ΔET-G (r=0.980) is greater than that of lgE0.5 and ET- X (r=0.883). It is concluded that the method of calculating the HOMO energy is better than that of detecting the oxidation potential during the study of QSAR of bis(4-dimethylaminophenyl)and its C-2 derivatives. According to the linear relationship obtained by AM1,bis(4-dimethylamino-2,6-fluorophenyl)squaraine has od photosensitivty.