The surface chemical state and morphology of as-deposited and post-heat-treated electrical bistable Ag-TCNQ thin films have been investigated with X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), respectively. The post-heat-treatment process promotes the reaction between Ag and TCNQ to form a complex, and finally Ag-TCNQ films with grain size of 50 nm and surface flatness in nanometer-scale have been obtained. XPS analysis reveals that the bonds between Ag and TCNQ are near cyan ends and cause new state of nitrogen originated by electrons transfer from Ag to TCNQ. (C) 2004 Elsevier Ltd. All rights reserved.