Solar flare is one of the most prominent manifestations of solar eruptions.The often-observed ribbon expansion is the prevalent phenomena of the solar flare.In this paper
a study about the correlation between the speed of flare ribbon separation and the magnetic field is presented.A weak negative correlation is found between the ribbon separation speed and the longitudinal magnetic field.This correlation is the weakest around the peak of the flare.The strongest reconnection occurs at the position of the HXR...