In order to study the effects of the parts coated by infrared low-emissivity material on the wall temperature and infrared radiation (IR) characteristics of the exhaust system, the wall temperatures and IR characteristics of the axisymmetric and serpentine 2-D exhaust system were measured in three coating schemes, i.e., (1) only central cone was coated; (2) only mixer inner surface was coated; (3) both central cone and mixer inner surface were coated, under the same experimental condition. The experimental results show that the temperature of the surfaces coated with low-emissivity materials increases, and that of the non-coating surfaces is also affected by the coating layer. When high-temperature parts are coated with low-emissivity materials, the IR intensity of the exhaust system can be effectively suppressed in detection angles where the coating surface can be directly detected, while in other angles the IR intensity varies with the coating scheme. It is appropriate to only coat the inner surface of the mixer for serpentine 2-D exhaust system, and coat the central cone and the inner surface of the mixer together for an axisymmetric exhaust system in order to achieve better IR suppression.