The explosive welding material of flame-resistant magnesium alloy (Mg-Al-Zn-Ca alloy: AZX611) and alminium alloy (Al-Mg-Si alloy: A6005C) was annealed at 473 K to 673 K and the characteristics of the intermetallic compound layer formed at the interface were clarified.When the explosive material was annealed, a layered structure was formed at the interface of AZX611/A6005C, and the thickness of layered structure increased with the annealing temperature. The layered structure was an intermetallic compound of Al and Mg, and it was estimated that it corresponded to β-Mg₂Al₃ when the annealing temperature was 473 K, and β-Mg₂Al₃ + γ-Mg₁₇Al₁₂ when the annealing temperature was 523 K or higher. The growth of the layered structure of the annealed material of the explosive welding clad material of AZX611/A6005C was also considered to be due to diffusion rate-determining.