This paper has described a method for synthesizing the potassium_expanded graphite intercalation compounds (K_EGICS), and discussed the electronic characteristics of expanded graphite and K_EGICS. It is found that electrical conductivity of K_EGICSgets smaller with the rising temperature (the electric conductivity decreases from 5.05×101S·cm-1to 2.35×101 S·cm-1when temperature rises from 77 K to 577 K), together with the elevation of graphite s EC (the electric conductivity goes up from 2.48×102S·cm-1to 5.769×102S·cm-1). The probable reasons for differences between expanded graphite and K_EGICSare also investigated.