Research on the Performance of Magneto-rheological Fluids Controlling Valve CHEN Gang1, PAN Yan-quan2, CHENG Hai-bin3,WANG Pin-hong1 (1.School of Machine Engineering,Hubei University of Technology, Wuhan 430068,China; 2.Department of Physics, Hubei Normal University, Huangshi 437000,China; 3. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China)According to the character of magneto-rheological fluids (MRF), a type of MRF controlling valve was designed.The performance was studied and the relationship among the pressure difference, the magnetic field and the load was tested. Besides the math modeling was made, ascertain the relationship between the pressure differences of the controlling valve and controlling electricity, which give a basis to practical use.magneto-rheological fluids; controlling valve; magnetic field; pressure difference