To efficiently construct a request load model that enables estimation of load information for a system on the basis of request information. A load estimation system comprising a management server that is connected to at least one object system, whereinthe management server comprises model generation means that generates a request load model in which load information for the object system is correlated with a classification of request into which request information for the object system is classified, andthe model generation means selects, in a process of the classification of the request information, the classification of request to be an object for sub-classification, based on estimation distribution information about the load information for each of the classification of request.