Based on meteorological and hydrological observed data,the character and physical cause of the ice run along Ningxia-Inner Mongolia Section of the Yellow River have been systematically analyzed.Statistical analysis of some factors that are interrelated to freezing up and melting of the river shows that the change of temperature is the main factor that affects the freezing up of the river,the river freezes up when the decadal mean temperature is lower than-5℃;meanwhile there is no critical air temperature index related to the thaw date of river ice,the date has a clear negative correlation with the temperature of Jan and Feb.Forecast equation was established through stepwise regression based on the factors created by Chebyshev polynomials,and it has proved to have good capability by the experimental forecast.