Based on meteorological and hydrological data observed at Inner Mongolia section of Yellow River during 1961-2009, we selected the DengKou and TuoKe Tuo stations, which are located in the upstream and downstream of the Inner Mongolia section respectively, to study the relationship between climate change and ice slush period using mathematical statistics method. Results are drawn as follows: (1) The air temperature in upstream is higher than that in downstream and the terrain gradient is small at Inner Mongolia section of the Yellow River, which lead to break-up in the upstream while freeze-up in downstream of the Inner Mongolia section. So ice slush motion is the most serious in this section. (2) Along with the climate warming, the break-up date of the Yellow River become early and freeze-up date become late, thereupon the ice slush period became short over the past 50 years. Especially after temperature occurring mutation in 1987, these changes became more obvious. Meanwhile the average temperature variation coefficient increases and temperature has dramatic change during the freeze-up period through the break-up period, which leads to acute fluctuation of ice slush period. (3) The key elements influencing the ice slush period at Inner Mongolia section of the Yellow River include -5 ℃ accumulative temperature, -5 ℃ lasting duration, air temperature and river runoff during the ice slush period, etc. Besides, the extreme temperature factors such as decrease of the number of coldness days, cold night index and cold day index, and increase of the warm night index and warm day index are also the reasons of the ice slush period shortening at Inner Mongolia section of Yellow River.