The design of novel conjugated polymers mainly consisting of porphyrin and/or phthalocyanine rings is Studied by the use of the tight-binding crystal orbital method based on the extended Huckel approximation. This paper focuses on the tuning of the electronic structures of these polymers by ethynyl bridging as well as various linkage modes. It has been clarified that the bridging sites (meso-to-meso, meso-to-beta and beta -to-beta) and the bridging patterns (linear or zigzag) in the ethynyl-bridged porphyrin polymers are crucial for tuning the pi -conjugation throughout the main chain. Furthermore, comparison of two-dimensional (2D) porphyrin polymer sheets and stacked porphyrin polymers demonstrates quite different electronic properties.