The crush tests for seven specimens of square tubes under axial compression are carried out, whose results are compared with the existing theoretical solutions and the empirical formulas with respect to the buckling load, the wavelength of the crushing mode and the mean crushing load. And also the finite element analysis is conducted by using the code developed in the previous report. The obtained results can be summarized as follows : (1) As for the buckling load the existing theoretical as well as the finite element solutions agree well with the experimental results. (2) As for the crushing wavelength the theoretical prediction fails, however, the finite element solutions which minimize the buckling loads are in quantitatively good agreement with the experimental values. The theoretical values given by Wierzbicki which minimize the rigid-plastic solutions for the mean crushing stresses also agree well with the experimental results. (3) As for the mean crushing load there is not a good agreement between the experimental results and the existing rigid-plastic solutions in which the strain hardening is not fully taken into account, while the empirical formula given by Magee et al. using the tensile strength instead of the yield stress has sufficient accuracy in spite of its simple form. (4) The complicated crushing deformations can be successfully simulated by the finite element method. The obtained mean crushing loads are about 25% smaller on the average than the experimental values because of the thick-walled effect, however, there is a good agreement between them from a qualitative point of view.