This study explores the growth behavior and rate-controlling processes of intermetallic compounds at Ag/Zn diffusion couple interfaces. Through experimental observations and quantitative analysis, we identify three distinct intermetallic compounds: β-AgZn, γ-Ag5Zn8, and ε-AgZn3. We analyze the kinetics of intermetallic compound growth to elucidate the mechanisms governing thickness growth in terms of interdiffusion and interface reactions. The rate-controlling process varies with temperature; volume diffusion controls layer growth at 573–593 K, while both volume diffusion and interface reaction contribute at 623–673 K. Additionally, we evaluate the activation enthalpies of parabolic coefficients, providing insights into the temperature dependence of growth kinetics and quantitation. This comprehensive analysis clarifies the intricate mechanisms underlying intermetallic compound formation, offering valuable implications for material performance and processing optimization in various applications.