A hysteresis model under different loading rate is proposed based on measurement results with simple polynomial method.This model will be used for better control and compensation of pneumatic actuator in actual application.The hysteresis model is achieved using simple polynomial method based on measurement data.Six groups of testing data are collected under different loading rate from quasi-static(2kPa/s)to 25kPa/s at growth rate of 5kPa/s.History independence research are also conducted in order to understand more detailed hysteresis feature of pneumatic actuator.Based on measurement results,it is concluded that the hysteresis model is effective to describe the effect of stroke and loading rate on the hysteresis.The history independence of hysteresis study validates the model is robust enough.