<p>The combined method of genetic algorithm and density functional theory (GA-DFT) has been used to study the size evolution and property of PdAg_<i>n</i> (<i>n</i> = 1–17) clusters. Benchmark calculations reveal that the TPSSH/def2-TZVP method is suitable. The structures of the clusters are planar or quasi-planar when <i>n</i> = 1–4, whereas they are three-dimensional when <i>n</i> = 5–17. The Pd atom favors to locate at the position with the highest coordination number. Moreover, the Pd atom likes to locate at the central position for PdAg_<i>n</i> clusters. Average bond lengths of Pd–Ag and Ag–Ag of PdAg_<i>n</i> (<i>n</i> = 1–17) clusters are recorded, which reveals that r_Ag-Ag and r_Pd-Ag increases as cluster size. The charge of Pd atom increases as cluster size. The average bond orders of Pd–Ag and Ag–Ag bonds decrease as cluster size increases. The peaks of the ultraviolet–visible spectra of the clusters increase as cluster size, and the peaks present odd–even oscillations as cluster size. The stability of PdAg_<i>n</i> clusters displays odd–even oscillation based on harness analysis and second-order energy difference analysis. According to thermodynamic analysis, the formation reactions of PdAg_<i>n</i> are spontaneous when the Ag atom adds to PdAg_<i>n</i>-1 clusters.</p>