Abstract: At present,the soda residue hasbeen widely used in landfill,and the strength characteristics are crucial to the analysis of the settlement and deformation of the soda foundation.The strength-deformation characteristic of the soda residue and the mechanism of the strength were studied and analyzed on the basis of triaxial test data of residue under different conditions.The conclusion was that the variation of shearing resistance agreed with the change of moisture content,density and age,and the maximum shearing resistance was not correlated with the optimal moisture content.It was different from the common soil.The cohesion would play a key role when the strength of soda residue was the maximum.