Electrochromic responses of metallophthalocyanines (MPcs) bearing redox active and electropolymerizable substituents were investigated. Excellent electrochromic responses were observed for metal-free and nickel phthalocyanines bearing electropolymerizable tetrahydroquinoline moieties (Phthalocyanine bearing 2,2,4,7-tetramethyl-3,4-dihydroquinoline, (THQ)) dyads; H 2 Pc-THQD and NiPc-DHQD). Although MPcs were not electropolymerizable complexes, they were easily electropolymerized on the working electrode after substituting with DHQ moieties. In order to investigate electrochromic features of the complexes, electrochemical and in-situ spectrochronocoulometric analyses of H 2 Pc-THQD and NiPc-THQD were first of all performed in solution and in solid states as their electropolymerized films to derive their possible usage as electrochromic materials. While both complexes gave common Pc ring based reduction reactions, they were coated on the working electrode with electropolymerization during oxidation reactions. Presence of THQ substituents caused electropolymerization of the complexes during the oxidation reactions. Then in order to examine their possible usages in the electrochromic application fields, phthalocyanine based composite electrodes were prepared with oxidative electropolymerization reactions. Finally their electrochromic features were investigated in different electrolyte systems. Electrochromic measurements showed that the electrodes modified with the electropolymerized films of H 2 Pc-THQD and NiPc-DHQD enhanced electrochromic properties to MPcs considerably. H 2 Pc-THQD and NiPc-THQD complexes illustrated excellent electrochromic parameters with high optical contrast, reasonable optical and columbic stabilities, and short response times.Phthalocyanines have been known as perfect functional materials for many decades, so multifarious technological applications have developed around these considerable interesting and enhanced materials. 1,2 Potential applications in technology such as photodynamic therapy (PDT), 3,4 optical data storage, 5 non-linear optics, 6,7 chemical sensors, 8,9 liquid crystals, 10-12 semiconductors, 13,14 and electrochromic device [15][16][17][18][19] and electrocatalyts in fuel cell and electrolysis 20-22 have shown increased significance of these macrocycles.Essential considerations for handling of phthalocyanines as electrochromic substances are particularly depend on their redox versatility, substitution alternatives with almost most metallic and some nonmetallic elements in the Pc central cavity, easy of modification by substituting the ring, easily coating on different surface (e.g. electrode) by various coating techniques and the most importantly electrochromic behaviors. 23,24 Although unsubstituted phthalocyanines are insoluble, substituting with different functional moieties increases their solubilities in common organic solvents and water. Especially long alkyl increases solubility of these complexes. 1,2 Although there are many paper on the electrochromism of phthalocy...