Acoustic emission (AE) technique has been applied to metallic and concrete structures as a nondestructive testing (NDT) method for detection of internal cracks. Current techniques employ PZT transducers for acquisition of AE signal. The work presented here describes development and testing of an AE sensor based on the optical fiber technology. It can monitor the crack signal in the concrete structure, for example, bridge, highway, tunnel and building etc., using the embedded optical fiber sensor.