The SiC fiber reinforced Ti55 composite (SiCf/Ti55) was fabricated by Fiber Coating Method (FCM) and Hot Isostatic Pressing (HIP). After the composites were thermally exposed in vacuum under different conditions, the study on the order of interfacial reaction products and the kinetics of interfacial reaction was performed. The results show that only C, Ti and Si elements take part in the interfacial reaction. The order of interfacial reaction products of SiCf/Ti55 composite exposed at 1000 °C can be identified as SiC | Ti3SiC2 | Ti5Si3+TiC | TiC | Ti55. However, the Ti3SiC2 does not exist in the composites exposed at low temperature. The interfacial reaction layer growth is controlled by diffusion and follows a role of parabolic rate, and the activation energy Qk and the pre-exponential factor k0 of SiCf/Ti55 composite are 198.16 kJ·mol-1 and 1.79′10-3 m·s-1/2, respectively. Compared with the SiCf/Ti composite and SiCf/Ti2AlNb composite, there is an interface with higher stability in SiCf/Ti55 composite. However, the interfacial reaction between SiC fiber and matrix takes place easier in SiCf/Ti55 composite than in the SiCf/Ti600 composite and SCS-6 SiCf/super а2 composite.