The polymer-based composite materials which have low-density and high performances are widely used. Especially, CFRP (Carbon Fiber Reinforced Plastic) is a next-generation lightweight material with high specific rigidity and specific strength. However, repeated low impact stress on these CFRPs can cause micro defects that are difficult to be detected with the bare eyes. Detecting such defects is crucial for repairing the flaws before they grow into fatal cracks. Complex and costly equipment should be used to detect such surface defects. This paper proposes a system that can reveal micro-sized defects on the surface of CFRP itself through a microcapsule containing photoluminescent materials. Photoluminescent material expelled from fractured microcapsules by impact can make the visual change, which enables the user to detect the initial defect. The CFRP with new material systems was investigated through various characterizations including OM, SEM, H-NMR, and FT-IR.