In this work, the influence of titanium interlayer thickness distribution on mechanical properties of Ti/TiN multilayer coatings is reported. Coating samples are deposited by arc ion plating on 304 stainless steel and (100) silicon substrates. XRD and SEM measurements are carried out to characterize the crystallographic structure and morphology of the sample coatings, respectively. Mechanical properties, such as hardness, indentation toughness, adhesion and residual stress, are evaluated. The effect of titanium interlayer thickness distribution on titanium grain size, hardness and indentation toughness is observed. Adhesion and residual stress show little dependence on titanium interlayer thickness distribution. The effect of titaniuminterlayer thickness distribution on coating mechanical properties is investigated and the mechanism is discussed with the support of finite element method. (C) 2017 Elsevier B.V. All rights reserved.