The influences on the geometrical structure, vibration frequency and electronic spectrum of substituents attached to the phenyl group on the meso-tetraphenylporphyrin (H2TPP) were performed by the density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. It was found that, except for slight deformation in derivative 8, there is little change in the porphyrin ring center structure, and the main influence position lies on the Cm atom. For the strong electron-donating group methoxyimino of derivative 8, we can find that the HOMO and LUMO energy levels significantly increased, and HOMO-LUMO Gap value reduced to 4.49eV. This means the strong Q band corresponds to the movement of electrons from the substituent to the porphyrin ring center, and produces a persistent absorption spectrum from UV to IR. Hence the derivative is possible to become efficient porphyrin photosensitizers in DSSCs.