In the experiments under transmission mode, the front side and rear side of 10 J impacted laminate are tested, respectively. In order to let heat conduct from surface to rear side, the greater heating time (1 s) and cooling time (500 ms) are applied. Some points (A, B, C, D and E) are selected to observe the temperature variation. Their locations are listed in Table 1. Fig. 8 shows the thermogram of front side of 10 J impacted laminate at 50 ms under transmission mode. The carbon fiber structure (including A and C) is clear and matrix (including B and D) is low temperature. However, it is difficult to identify the impact. Fig. 9 shows the thermograms of front side and rear side of 10 J impacted laminate at 1 s under transmission mode. In Fig. 9a, points A–D show the high temperature and there is a circle shape higher temperature around impact like Fig. 7a. However, the middle area (concavity) does not show the higher temperature. The circle shape of higher temperature indicates that the lower conductivity caused by impact is focused