The nanostructured Ti/Ta and Ti/Zr multilayers with equal layer thicknesses h ranging from 2.5 to 150 nm were prepared by using magnetron sputtering technique. Their rate dependent deformation behaviors were explored by nanoindentation. With reducing h , the strain rate sensitivity m of Ti/Ta multilayers decreased from a positive value to negative at the critical h * of ~ 20 nm, at which the hardness is insensitive to strain rate. While the m of Ti/Zr multilayers decreased as the decreasing of h. This evolution of strain rate sensitivity in multilayers was interpreted in terms of the heterogeneously interfacial structure, i.e., the constituent interlayer coherent interfaces and phase boundaries in nanolayers. The deformation morphologies after nanoindentation were observed and discussed to further examine plastic deformation and dislocation activities of multilayers. • The formation of coherent interfaces decreases SRS of Ti/Ta and Ti/Zr multilayers. • The SRS platform is obtained in Ti/Ta due to the competition between coherent interfaces and incoherent phase boundaries. • Pile-ups deformation morphologies after nanoindentation which related with dislocation activities are observed. • The influences of interface structures and grain orientation on dislocations propagation were discussed. [ABSTRACT FROM AUTHOR]