Abstract: The rheological behavior of the suspension consisted of alumimum-magnesium hydrotalcite-like compounds(Al-Mg-HTlc) with permanent positive charge and Na-montmorillonite(Na-MT) with permanent negative charge have been studied as function of the applicability of the Bingham rheological equation and the Brinkman viscosity equation. The influences of Al-Mg-HTlc/MT mass ratio(R) on apparent viscosity(η_A), Bingham yield stress(τ_B) and E-B coefficient(K) were also investigated. The results show that the suspension with ω(MT)=1.5% and the Al-Mg-HTlc/MT suspension with the same MT, contnet and R=0.2 belong to Newtonian fluid; the pure MT suspension with ω(MT)≥3% and the Al-Mg-HTlc/MT suspension with ω(MT)≥3% belong to pseudoplastic fluid. The pure MT suspension conforms to the Bingham rheological equation, whereas the Al-Mg-HTlc/MT suspension conforms to the Bingham equation only at high shear rate (D=300~1100 s^-1). Both the pure MT suspension and Al-Mg-HTlc/MT suspensions conform to the Brinkman viscosity equation in the range of 0~1022 s^-1 shear rate. All the η_A, τ_B and K values were found increased with increase in R and went through a maximum at R around 0.25. The mechanism of interaction between the particles and the characteristic parameters were discussed. It is concluded that the E-B coefficient K of the Brinkman viscosity equation is the ‘Intrinsic Rheological Parameter’, characteristic of the internal interaction among the particles of the system.