Abstract: The discharge of dye effluents from textile, cosmetic and food industries into the aquatic environment is a serious environmental concern. Most of the dyes are difficult to decomposing to its highly toxic and chemically stable nature. In recent decades, photocatalysis using semiconductor nanoparticles has been received tremendous attention for the degradation and mineralization of variety of organic pollutants (dyes, phenols, pesticides and pharmaceuticals) in aqueous media. In the past few years, CuO has attracted increasing interest for both fundamental and practical reasons. It has been shown that CuO is an important industrial material that can be widely used in applications such as gas sensors, magnetic storage media, solar-energy transformation, electronics, semiconductors, varistors, and catalysis. CuO is a p-type semiconductor. The direct band gap energy of CuO nanorods is evaluated to be 2.75 eV (450.85161nm). We use a simple wet-chemical method for preparing CuO nanorods in the presence of a nonionic surfactant, polyethylene glycol (PEG; Mw= 20 000). This method requires neither complex apparatus nor long synthesis times. CuO nanorods can be prepared easily and effectively without complicated control of the reaction conditions. Cuo do not destroy methylen blue in visible light well. Beacuse its band gap almost is on violet region. We synthesized Cuo functionalized with porphyrin for first time. Tetrakis (4-carboxyphenyl) porphyrin (TCPP) was prepared by reflaxing 4-Carboxybenzaldehyde and pyrrole in propionic acid. The photocatalytic activity of synthesized catalyst was investigated in degradation of methylene blue under visible light irradiation.