A time factor feature generation system includes: a use status grasping portion that extracts transition data showing variations in degree of use of a site from log data; a variation data generating portion that generates, based on the transition data, variation data expressing the variations in degree of use of the site as a group Y of values showing the degree of use of the site; a time factor data recording portion in which a plurality of time factors and time factor values of each of the plurality of time factors are recorded; a time factor extracting portion that generates groups Di of time factor values, each of which corresponds to a time factor extracted from among the plurality of time factors; and a time factor feature generating portion 13 that calculates coefficients ai such that a square of an error b has a minimum value in an equation in which the groups Di and the group Y are used as an explaining variable and an explained variable, respectively, thereby to generate data showing a time factor feature of a use status of the site. By this configuration, the time factor feature generation system generates data quantitatively showing a time factor feature of a use status of a site.