This study was conducted to prepare some complexes by using Tryptophan as a ligand with some metal chlorides including (Cadmium, Zinc, Nickel, Copper, Chromium, and Cobalt). The resulting combinations have been demonstrated by using infrared analysis (IR) and thermodynamic analysis (TGA) Also some of physical properties such as electrical conductivity, complex color and melting point were estimated for each complex. The potentiometric studies were carried out to estimate the thermodynamic parameters and ionization and stability constants.