Abstract: In the solution of (0.4 mol KOH + 0.6mol NH₄Cl )/L PH = 9.5 TPPS produces three po-larographic waves. The first step of reduction which involves 2H⁺ is a 2e reversible electrodeprocess. Being coordinated with Zn(Ⅱ), the complex of ZnTPPS gave two reduction wavesand one oxidation wave. The first reduction wave of ZnTPPS is reversible and involves oneH⁺. Redunction of Zn²⁺ during or after the first reduction wave may result from the disso-ciation of ZnTPPS. The nearly equal strong adsorption of TPPS and ZnTPPS on Hg electrode was observedand Γ⁵⁰,β₀, K₀ and √G⁰ were cal culated.

Key words: meso-tetra-(P-su'phenate-phenyl)porphyrin, meso-tetra(P-sulphonate-phenyl)zine(Ⅱ)porphyrin, voltammetry