The Ru (Ⅱ) complexes, [Ru(Pc-(COOH)n)(NCS)2]2-(labeled as Pc-n) and [Ru(Por-(COOH)n)(NCS)2]-(Por-n) (n =0-4), are theoretically studied on their photophysical properties.A reference molecule [Ru(Pc)(pyCOOH)2] with experimentally known spectral data has been calculated to choose a reasonable theoretical approach.The calculation results indicate the number of COOH groups can significantly influence optical properties and electronic structure of Pc-n and Por-n complexes, but has a slight on their geometry structure.Compared with phthalocyanine derivatives, porphyrin-complexes have a restively large integral area of absorption spectra in the visible region.The atomic spin density analysis also indicates that the ligand which is modified by the COOH groups is the ideal spot for the captured electron to be localized on.It can be predicted that with the increase in the number of carboxylic acid, absorption spectrum have a pronounced red shift.