The kinetics of dissolution and transformation process of 2MgO·2B2O3·MgCl2·14H2O in 4.5% H3BO3 aqueous solution at 50℃ was studied.The liquid samples were taken at different time for chemical analysis,and the solid phase at different stages was separated and identified.The experimental results showed that 2MgO·2B2O3·MgCl2·14H2Odissolved congruently in 4.5%H3BO3aqueous solution,which was different from the process of the dissolution of 2MgO·2B2O3·MgCl2·14H2O in water.The final solid phase was kurnakovite（2MgO·3B2O3·15H2O）.The kinetic equations of the crystallization reaction were given with the aid of Simplex Optimum Method and Runge-Kutta digital solution of differential equation system.The mechanism of dissolution and transformation were proposed and discussed.
