A leg fixing device, which connects together the leg and the hull of a jackup rig, is indispensable when the jackup rig develops oil and gas in harsh environment such as the North Sea, and it takes severe load through its several teeth in contact with the several teeth of the opposite leg rack. Accordingly, it is very important to know the strain distribution, deformation and ultimate strength of one pair of mutually contacting opposite teeth, and the load distribution and ultimate strength of several pairs of mutually contacting opposite teeth from the design point of view. In this paper, four kinds of scale models of leg fixing device, three were 1/4 scale (one pair of opposite teeth) and the rest 1/8 scale (six pairs of opposite teeth), were tested up to the ultimate load state, and the analysis of the models was performed by the finite element method as elasto-plastic contact problem. The results of calculations were compared with those of experiments and the following conclusions were obtained. (1) Characteristics of strain field of one pair of opposite teeth from elastic state to ultimate strength state were shown by the calculation and the calculated equivalent plastic strain distribution showed that the mechanism of failure of one pair of opposite teeth derives from shear. (2) Like the contact problem of circular cylinder and flat body, both calculations and experiments showed that the relation between load and displacement of one pair of opposite teeth was concave in elastic state and changed convex after elasto-plastic state started. (3) Both calculations and experiments confirmed that the ultimate strength of one pair of opposite teeth was obtained by the simple equation proposed in Ref. 1). (4) Simplified analysis method to estimate the load distribution of several pairs of opposite teeth was shown and found useful by the comparison between the results of calculation and experiment. (5) Concerning n pairs of opposite teeth, the calculation showed that uneven distribution of tooth load in elastic state became almost even in ultimate strength state and both the calculation and experiment showed that the ultimate strength of n pairs of opposite teeth was n times the ultimate load of one pair of opposite teeth.