Growth rates of boric acid have been measured both in the absence and in the presence of electrical field at 1.00 DC voltage as a function of supersaturation in a laboratory-scale fluidized bed crystallizer at the temperature range of 20 degreesC to 52 degreesC. The values of overall rate coefficient (K-G) diffusion rate coefficient (k(d)) reaction rate constant (k(r)) and reaction order (r) were determined by trail and error method at different temperatures. In the absence of electrical field increasing the temperature causes to increase the values of K-G, k(d), k(r) and r.. Activation energies are also determined for K-G, k(r) and k(d) separately. The effect of electrical field on the crystallization steps were determined by similar route. It was observed that electrical field caused to decrease the values of kinetic parameters (K-G, k(d), k(r) and r) by increasing temperature.