Dissolutionof La in KCl-NaCl and LaCl_3-KCl-NaCl melts has been investigated by meansof a transparent cell,cyclic voltammetry and EHMO of quantum chemistry.It is shown thatthe La dissolved in KCl-NaCl melt exists in a metallic state,the La dissolved inLaCl_3-KCl-NaCl melt can be ionized into La~(2+) as a result of reaction with La~(3+),furthermore,the La~(2+) reacts with La~(3+) forming atom cluster La_m~(n+) which is a stable state inthe melt. Dissolution of La in KCl-NaCl and LaCl_3-KCl-NaCl melts has been investigated by means of a transparent cell, cyclic voltammetry and EHMO of quantum chemistry. It is shown that the La dissolved in KCl-NaCl melt exists in a metallic state, the La- In LaCl3-KCl-NaCl melt can be ionized into La ~ (2+) as a result of reaction with La ~ (3 +), furthermore, the La ~ (2+) reacts with La ~ (3+) forming atom cluster La_m ~ (n +) which is a stable state inthe melt.