We report the complementary resistive switching (CRS) origins of two hetero TiOx/TiN/TiOx and TiOx/TiOxNy/TiOx matrix, allowing for the possible memory operation without the use of selection device. Each matrix consisted of anti-serially combined bipolar switching elements 1 and 2, where one bipolar switching element 1 was Pt/topTiO(x)/bottom TiN or TiOxNy, and the other switching element 2 was top TiN or TiOxNy/bottom TiOx/Pt. The electrical properties of the two matrices suggested that the nature of CRS behaviors was based on a combination of the filamentary conduction paths in the top and bottom TiOx layers and the redox reaction induced by oxygen ion drift at the interfaces of the middle TiN and TiOxNy layers. (C) 2013 Elsevier B.V. All rights reserved.