The electrical bistability of the two kinds of complex thin films Ag-TCNQ and Ag-BDCB was discussed,which were films of metallic clusters embedded in π-conjugated organic media.And infrared spectroscopy was applied to the study of the mechanism.The pump-probe method was used to study the transient response of these two kinds of thin films, the therotical analysis demonstrates that the transient response can be associated with the electrical stability qualitatively.