The electrochemical migration (ECM) behavior of the electrically conductive adhesives (ECAs) filled with pure Ag powder or Ag-plated Cu composite powder with varied Ag:Cu ratios was investigated under the condition of applying constant voltage and distilled water environment.ECM resistance was determined from the current-time curves.The microstructure and composition of ECM dendrite products were analyzed by SEM/EDS and XRD.It was found that the ECM resistance of Ag-plated Cu composite powder-filled ECAs was evidently higher than that of pure Ag powder-filled ECAs.The Ag:Cu ratio of composite powder in ECAs had notable influence on ECM resistance,which was enhanced with the decrease of Ag:Cu ratios.The composition of dendrites formed between cathode and anode during ECM process was not uniform for Ag-plated Cu-filled ECAs.An ECM inhibiting mechanism of Ag-plated Cu composite powder was proposed according to analysis of the electrochemical impedance spectroscopy,Tafel plot and dendrite composition. The electrochemical migration (ECM) behavior of the electrically conductive adhesives (ECAs) filled with pure Ag powder or Ag-plated Cu composite powder with varied Ag: Cu ratios was investigated under the condition of applying constant voltage and distilled water environment. ECM resistance was determined from the current-time curves. The microstructure and composition of ECM dendrite products were analyzed by SEM / EDS and XRD. It was found that the ECM resistance of Ag-plated Cu composite powder-filled ECAs was evidently higher than that of pure Ag powder-filled ECAs. Ag: Cu ratio of composite powder in ECAs had not been affected on ECM resistance, which was enhanced with the decrease of Ag: Cu ratios. composition of dendrites formed between cathode and anode during ECM process was not uniform for Ag-plated Cu-filled ECAs. Ann ECM inhibiting mechanism of Ag-plated Cu composite powder was proposed according to analysis of the electrochemical impedance spectroscopy, Tafel plot and dendrite composition.