The need to develop and use light weight structural components in the design of aircraft and automotive vehicle has brought increasing application of composite materials. Composites have various kinds of flaws built into them during manufacturing process. Similar looking composites may have quite different properties depending upon their internal features. Reliable performance of the advanced, high strength material in critical applications depends on assuring that each part place in a service satisfies the conditions assumed in design. This research addresses the use of half power bandwidth method to experimentally measure the damping of a carbon fibre/epoxy composite. Additionally the dynamic stiffness was also measured. The effect of moisture, humidity and fibre orientation on dynamic characteristics of composite was investigated to work out the best layup sequence for a structure.