In order to predict the forcevelocity behavior of a magnetorheologica l (MR) damper with a hole duct valve，a quasistatic axisymmetric model of was bu i lt based on the HerschelBulkley and Bingham models， the pressure gradient equ a tion was derived. For the HerschelBulkley model，the pressure gradient equatio n was solved numerically，and for the Bingham model，the analytical solution of t he pressure gradient equation was obtained by using the algebraic equation theor y. An example of simulation was presented to predict the velocity profile of the MR fluid through the hole duct valve and the damping force.