Abstract: In order to find the solutions of a cylindrical cavity expansion, the stress distribution due to the cylindrical cavity expansion in soil is considered as elastic and plastic regions. The deformation following a little deformation in the elastic zone and the large-deformation in the plastic zone is taken into consideration. On the bases of the stress equilibrium equation and continuous boundary condition of stress and deformation, the stress distribution in elastic and plastic regions, the terminal radius and cylindrical cavity expansion pressure are obtained. According to the comparison, the result of the present theory is very near to that of the Vesic’s theories. The cavity expansion pressure and plastic radius affected by dilation is more than parameter of b.