Mechanical properties of conditioned soils in EPBM tunneling consist of lots of unknowns. In this research, the tests has been arranged to fulfill of four goals. Firstly the effects of conditioning on the shear strength variation have been investigated. Secondly an investigation on effects of conditioning on shear strength parameters (C,ϕ) has been performed. In third step the results exerted from two previous stages have been compared for two shearing apparatuses of conventional and large shear boxes. The last goal of the research is exploration of effects of changes in conditioning parameters on shear strength. It is found that the C&ϕ for tested soils obtained from large shear box are usually greater than the results of the same soil in conventional shear test. This result is less significant for conditioned soil with compared to unconditioned soil and it is found to be a function of injected foam content.