Abstract: The strength and deformation behavior of municipal solid waste(MSW) with different composition was studied.A bilinear strain hardening model was proposed based on the results from the static triaxial tests under loading-unloading-reloading conditions.Furthermore,a complete set of model parameters including unloading modulus and Poisson’s ratio were determined.It was shown that stress-strain relationship of MSW was significantly affected by MSW composition and its compacted density.MSW was divided into two categories based on the ratio of organic fraction to inorganic fraction,and different models were used to describe corresponding types of MSW.It was found that there were marked strain hardening characteristics in the stress-strain relationship of MSW when the majority of its composition was organic component,and a bilinear model was proved to be more reasonable to describe this type of MSW.Whereas,the stress-strain behavior of MSW was similar with that of soil when the majority of its composition was inorganic,and the hyperbola model could be used to describe the stress-strain relationship of this type of MSW.