High-quality CuInS2 (CIS) thin films have been fabricated by sulfurization of electrodeposited copper indium bilayer. A novel bell-like wave modulated square wave (BWMSW) electrodeposition technique is employed for the deposition of copper thin film. Three independent parameters (current or potential, frequency, duty cycle) are available for the BWMSW electrodeposition, which is different from the traditional electrodeposition technique with only one adjustable parameter (current or potential). The influences of deposition parameters such as frequency, duty cycle and the concentration of complexing agent are investigated. Benefited from the high quality copper film obtained by the BWMSW technique, the indium film is electrodeposited successfully on the copper layer to form a compact copper-indium alloy bilayer. After sulfurized at 600 degrees C for 60 min, the phase pure CIS film is obtained with better crystallinity. The structures, morphologies and optoelectronic properties of the CIS film are also characterized. (C) 2015 Elsevier Ltd. All rights reserved.