Abstract: Soil has different moduli in tension and compression.In order to obtain a more precise solution of spherical cavity expansion,an analysis of spherical cavity expansion in elasto-plastic soil is presented based on the elastic theory considering different moduli in tension and compression.The characteristics of dilation are taken into account by using the non-associated Mohr-Coulomb yield criterion.The analytical solutions for the stresses in elastic and plastic zones,maximum radius of the plastic zone and expansion pressure are obtained.The influences of different tension and compression modulus ratios,Poisson’s ratios and dilation angles on the expansion pressure and radius of plastic zones are discussed.The results show that different tension and compression modulus ratios,Poisson’s ratios and dilation angles have significant influences on the development of plastic zones and the stresses in the soil.Large errors will occur if these parameters are ignored.