Based on the Navier-stokes equations in hydrodynamics,quasi-static flow governing equations for magneto-rheological(MR) fluids in plates channel are theoretically set up by analyzing force equilibrium on fluid element and making several rational simplifications.Analytical velocity profiles of MR fluids though the plates channels are obtained via solution of the quasi-static flow equations mentioned above using Biviscous constitutive model,those boundary conditions and compatibilities.The formula used to calculate damping force offered MR fluid damper is formulated and damping performances are predicated in order to determine design parameters.In the light of technical requirements for front suspension for ChangAn mini-bus,MR fluid dampers are designed and fabricated in Chongqing University.Measurements from sinusoidal displacement cycle by ShanChuan Shock Absorber Ltd.reveals that the analysis methodology and design theory are reasonable.