Abstract: Thick film humidity sensors were prepared by the screen-printing technique starting from MnWO₄-Li₂WO₄ system powders,the MnWO₄ obtained by solid state reaction with the MnCO₃ and WO₃ which was prepared by sol-gel method.The experiment results show that the prepared sensor by MnWO₄ doping Li₂WO₄ of 30mol% has several main features such as the lower resistance at lower humidity,high sensitivity,quick response and small humidity hysteresis.These features are important to the practical use of this material system.The SEM photograph and complex impedance analysis indicate that the thick film humidity sensor has a better microstructure of the nanometer crystal grain and crystal boundary which is the important factor influencing the humidity sensing performance.