A substituted tetraphenylporphyrin silicon complex is represented by the general formula (I): wherein R1, R2, R3, R4, and R5 independently denote a hydrogen atom, an alkyl group, an alkoxy group, or a polyalkyleneoxy group, providing that the case in which R1-R5 invariably denote a hydrogen atom is excluded, and X and Y independently denote a hydroxyl group, an alkoxy group of C1-C3, or a halogen atom is disclosed. This invention embraces a substituted tetraphenylporphyrin silicon complex, polysiloxane, polysilane, liquid crystal material, photoconducting element, and photo-functional chaarge transfer material.