Cement-mixing method is gaining popularity as a method for stabilizing soft soils in applications ranging from the improvement of foundation properties to mitigation of liquefaction. However, spatial variability in the shear strength of the cement-mixed ground introduces uncertainties in estimating the bearing capacity for design. This paper presents a reliability assessment for the bearing capacity of cement-mixed ground based on the results of a probabilistic study in which the shear strength of the cement-mixed ground is represented as a random field in Monte Carlo simulations of undrained stability for a surface foundation using numerical limit analyses. The results show how the bearing capacity is related to the coefficient of variation and correlation length scale in the shear strength of cement-mixed ground. Finally, the reduction of bearing capacity due to spatial variability of shear strength in cement-mixed ground is evaluated based on the result of the application to construction sites by cement-mixing in Japan in terms of probabilistic point of view. Copyright ASCE 2009.