It was studied the effects of the exchangeabl e Ca2+ and Mg2+, the cation exchange capacities and the saturation Index in basis over the zinc fixation by 30 soil samples, using the 65zn as a tracer element. It was found positive and significative correlation at 1% among the Zn fixation and the mentioned variables. The results, however, are not conclusives and the authors keep the oppinion that more experiments must be done in order to elucidate the subject.