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It is generally believed that the bimetal interfaces play a critical role in governing the deformation mechanism and plastic behavior by tuning the dislocation nucleation and slip transmission across the interface.By comparison of semicoherent and incoherent interfaces,we show that the interface type and misfit dislocations determine the nucleation mechanism of lattice dislocation or dissociation paths of misfit dislocations at incoherent fcc/bcc interfaces.By means of large scale atomistic simulations,we found that the coupling of interface and nanosize effect will govern plastic resistance and dynamical behavior of the nanolaminate materials.Two regimes of plastic deformations are revealed as: the nucleation of lattice dislocations is energetically more favored at the interface when the layer thicknesses are lower than 20nm; when layer thickness approaches about 5 nm,the peak resistance is observed for the dislocation nucleation due to the combined effect of nanosize and interface structure,and then a decreasing resistance is found with the finer layer thicknesses,where dislocation transmission across the interfaces becomes more frequent.The slip systems of the nucleated dislocations are found to be related to the geometrical compatibility of pairs of slip systems between neighbor crystals,while the transmission site is strongly linked to the interface misfit dislocation network.