The restoring force characteristics of the usual column bases are shown to be the slip-type ones, and the plastic deformation of the column base is due to monotonic tensile deformation of the anchor bolts. The experiments of the column base with thin base plate, and of the column base with anchor bolts tightened in time were carried out last year. The restoring force characteristics are modeled and compared with the experimental results. The analytical models are in good agreement with the experimental ones.