Abstract: Calcium chloride and sodium chloride were used to regulate conductivities of protonize pulp which had been added different chemical agents. Zeta potential of pulp was detected by mütek SZP-04 and quantitatively analyzed with Minitab software. The results showed that inorganic ions brought down the absolute value of Zeta potential of the pulp. The reduction effect on the absolute value of Zeta potential of the pulp from calcium ions was stronger than that from sodium ions. The mathematic relationship of the Zeta potential of the pulp(ζ), the conductivity of pulp(σ) and the original Zeta potential of pulp(ζ0) met the following mathematic models: when regulating conductivity of pulp by calcium chloride:ζ=-0.388+0.988ζ0+0.202lnσ-ζ00.091lnσ; When regulating conductivity of pulp by sodium chloride:ζ=-0.806+0.960ζ0-0.316lnσ-ζ00.102lnσ. As the Zeta potential approached zero, the drainage and retention ability of CPAM approached optimum. Compared with sodium ions, calcium ions was easy to bring up the Zeta potential of pulp so high to positive charge, the ability of pulp was affected accordingly.