The Rashba effect of surface alloys of semimetallic bismuth (Bi) is strongly related to its specific structural properties. The initial growth behaviors of Bi atoms on Ag(111) and Au(111) are systematically investigated by combining scanning tunneling microscopy (STM) and density flooding theory (DFT) in this paper. Continuous Ag2Bi alloy films are formed preferentially at the step edge on Ag(111) held at room temperature; Bi atom replaces step edge atoms with low coordination number and is randomly distributed from single atoms to form long-range ordered Ag2Bi alloy phase as the coverage increases to 0.33 ML on Ag(111) held at 570 K. With increasing coverage, Ag2Bi is converted to Bi films with p×√3 structure by the dealloying process. In contrary to Ag(111), Bi growth behavior on Au(111) held at room temperature and 570 K is consistent: Bi atom preferentially adsorbs on Au atom pairs with coordination 5 and is dispersed as single atoms and clusters in the densely packed region and at the corners of the herringbone reconstruction when coverage levels below 0.40 ML; as the coverage level increases to 0.60 ML, the disordered Bi gradually transforms into the long-range ordered (√37×√37) phase. Moreover, the adsorption of Bi leads to the gradually release of Au(111) surface strain. The different growth behaviors of Bi on Ag(111) and Au(111) suggest that the interaction between Bi atoms and the substrate plays a key role. Bi atoms preferentially adsorb around atoms with low surface coordination number under low coverage.