Electrochemical kinetic investigation of a Ti-H system was conducted in LiCl-KCl-LiH melts at 723 K. Apparent chemical diffusion coefficients of hydrogen including phase transformations, D-H('), were estimated for alpha, alpha + beta, beta, and beta + delta phases by chronopotentiometry Chemical diffusion coefficients of absorbed hydrogen D-H in alpha, beta, and delta phases were obtained by ac impedance spectroscopy and that in delta phase was estimated by potential-step chronoamperometry. Obtained results were compared with reported values to confirm the validity of the electrochemical technique for kinetic investigation of M-H systems in both cases, with and without phase transformations. (X) 2001 The Electrochemical Society.