The unloading creep properties of soft soil under the excess pore water pressure are important for analysis of the deformation and stability of underground excavation in water-rich soft soil region. In this paper, the silty soft soil in Shenzhen was investigated via conducting unloading K₀ consolidation undrained triaxial test and unloading creep test under different initial static pore water pressures. Results show that a higher initial excess pore water pressure and a smaller consolidation confining pressure will cause more abrupt unloading failure of the soft soil. The stress-strain curve of the unloading strength of soft soil is in the form of hyperbola. The results of hyperbolic function fitting show that the unloading strength decreases linearly with increase of initial excess pore water pressure. The unloading creep deformation is found to be sensitive to the initial excess pore water pressure. The failure deviatoric stress in unloading creep test is about 90% of the deviatoric stress in unloading strength test. The unloading failure and creep failure are more likely to occur under stress path with UU0.5 compared with UU0.0. Therefore, the confining unloading rate and the excess pore water pressure should be cautiously controlled in engineering practice.