In　this　paper,　the　vibratory　properties　and　expression　of　natural　modes　of　laminated　composite　beam　with　variable　cross-section　ratios　of　elastic　modulus　and　density　along　the　axis　of　the　beam　have　been　investigated　via　theoretical　analysis.　Based　on　the　generalized　Hamilton　principle,　the　longitudinal　and　transverse　vibration　equations　have　been　deduced　by　the　means　of　variational　method.　Then,　the　natural　frequencies　of　longitudinal　and　transverse　vibration　modes　have　been　obtained　using　the　method　of　power　series,　which　agree　well　with　finite　element　simulations.　The　first-order　natural　frequencies　of　longitudinal　and　transverse　of　composite　beams　are　plotted　as　a　function　of　the　elastic　modulus　or　densities　difference　of　two　components.　With　distinct　material　characteristics,　the　effect　of　shape　factor　on　the　first　and　second　order　lateral　modes　of　composite　beam　is　also　revealed.　In　addition,　the　study　shows　that　the　boundary　conditions　impose　a　strong　effect　on　the　shape　factor.　The　method　presented　in　this　paper　is　not　only　suitable　for　the　laminated　composite　beam　with　variable　cross-section,　but　will　also　be　applicable　to　more　general　cases　of　composite　beams　of　complex　geometry　and　component　in　vibration　mechanics.　This　controllable　vibration　performance　achieved　in　this　paper　may　shed　some　light　on　and　stimulate　new　architectural　design　of　composite　engineering　structures.