By quantitatively adding the leaching agent to the clay minerals dropwise and continuously measuring their zeta potential, pH and conductivity as well as taking samples to determine the rare earth content in the solution, it was found that the variation of zeta potential was related to the leaching content of rare earth ions and was linearly correlated, and the more rare earth ions were leached, the more negative zeta potential was. The relationships between the changes of Zeta potential, pH and conductivity of the three leaching agents, ammonium sulfate, magnesium sulfate and aluminum sulfate,