The predecessors' research results about the overland flow resistance are summarized from the following four aspects that the influence of overland flow resistance on slope surface flow pattern, the relationship between overland flow resistance and Reynolds number, the influence of rainfall on slope surface flow resistance, and overland flow resistance formula characterization. The result indicated that the uncertainty of slope surface flow pattern led to the more complicated change of overland flow resistance;there is no single good correlation between the overland flow resistance and Reynolds number; rainfall has a great influence on slope surface flow resistance but the specific influence mechanism is not clear;open channel flow concept and expression are still used in characterization of overland flow resistance formula, and there is no unified conclusion that which is more suitable for characterization of overland flow resistance of three resistance coefficients n、f、C. The paper analyzed the existing problems and prospect the future development as well. In order to study the overland flow resistance in a more comprehensive and systematic way, it is necessary for us to make a breakthrough in research method, experiment equipment and measurement technology.