The embedded structural health monitoring system is envisioned to be an important factor of future structural systems. One of the many attractions of in situ health monitoring system is its capability to inspect the structural systems in less intrusive way over many other visual inspections which require disassembly of built up structures when some indications have appeared that damages have occurred in the structural systems The vacuum assisted resin transfer molding (VARTM) process is used to fabricate woven-glass/phenol composite specimens which have the PZT sensor array embedded in them. The embedded piezoceramic (PZT) sensors are used as both transmitters and receivers. A damage identification approach is developed for a woven-glass/phenol composite laminates with known localized defects. Propagation of the Lamb waves in laminates and their interactions with the defects are examined. Lamb waves are generated by the high power ultrasonic analyzer. A real time active diagnosis system is therefore established. The results obtained show that satisfactory detection accuracy could be achieved by proposed method.