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This paper discussed the intermetallic compounds (IMCs) in the copper-aluminum brazed joints during formation and application through reviewing some recent research on brazing copper to aluminum. The review indicated that it was difficult to avoid the formation and growth of the IMCs, which depends on the mutual diffusion between Cu substrate and Al substrate as well as substrates and filler metals. Thermodynamics and kinetics are critical for the nucleation and growth of the IMCs respectively. Besides, defects (voids, cavities and cracks) in the joint mainly result from the formation and growth of the brittle IMCs because it always results in stress concentration as the source of cracks and accelerates the excessive consumption of the diffused atoms to form voids and cavities. Properties of copper-aluminum joints were severely deteriorated when the thickness of the IMCs exceeds 2~5μm. Finally, numerous factors (melting point, thermal conductivity, joint design, heat input and chemical composition) strongly impact the formation and growth of the IMCs through changing the mutual diffusion process. Moreover, these factors also have distinct effects on the defects. At present, some efficient methods used to control the IMCs in the copper-aluminum joints are heat input controlling, optimization of joint design and the addition of the third element into filler metals.