How to model pedestrian movement is an intriguing problem in the area of statistical physics. As a common phenomenon of pedestrian movement, fatigue has a significant negative eect on pedestrian movement, especially when pedestrians move or run with heavy luggage, rescue the wounded in disaster, climb stairs and etc. According to the field observations and previous researches, fatigue coecient is defined as the decrease of desired velocity in this study. However, previous researches lacked quantitative analysis of the eect of fatigue on pedestrian speed. It has been a great challenge to study the eect of fatigue on pedestrian flow, since pedestrians of heterogeneous walking abilities and the change of pedestrians' moving properties need to be taken into consideration. Thus, at first, a series of pedestrian experiments, under three dierent conditions, were conducted to formulate the empirical relationship among fatigue, average free velocity, and walking distance. Then