This paper presents the application of a Michelson interferometric fiber-optic sensor for monitoring the damage of fiber-reinforced plastics. A Michelson interferometric fiber-optic sensor was mounted on the surface of unidirectionally aligned carbon fiber-reinforced epoxy composites. Response of the interference signal to either dynamic or static loading was investigated. Specimen being impacted, the optical interference signal dropped suddenly and then oscillated. The tensile test was performed with the measurement of optical interference signal, strain as well as acoustic emission. Both fast Fourier transform and digital filter processing of the optical interference signal were carried out to characterize the damage signal from the fiber-optic sensor. The optical interference signal whose frequency ranged from tens to hundreds Hz occurred when the specimen was damaged. It was shown that real-time information comparable to acoustic emission (AE) data could be obtained from Michelson interferometric fiber-optic sensor through a digital filtering technique. The Michelson interferometric fiber-optic sensor proved to be effective for monitoring the damage processes of the material studied.