A　system　of　Mathieu-Hill　equations　have　been　obtained　for　the　dynamic　stability　analysis　of　electrical　graded　piezoelectric　circular　cylindrical　shells　subjected　to　the　combined　loading　of　periodic　axial　compression　and　radial　pressure　and　electric　field.　Bolotin＇s　method　is　then　employed　to　obtain　the　dynamic　instability　regions.　It　is　revealed　that　the　piezoelectric　effect,　the　piezoelectric　graded　effect　and　the　electric　field　only　have　minor　effect　on　the　unstable　region.　In　contrast,　the　geometric　parameters,　the　rigidity　of　constituent　materials　and　the　external　loading　play　a　dominant　role　in　determining　the　unstable　region.