This study examines four types of Bi-xAg alloys (where x = 1.5, 2.5, 5.0, and 7.5 wt%) prepared using a casting method. The effects of Ag addition on the microstructure and properties of the alloys, as well as their deformation behavior at low strain rate (1.0 × 10−5s−1) were investigated. With the increase of Ag content, the microstructure variation and grain refinement are noticeable, the ultimate tensile strength increases, and the fracture strain first increases and then decreases, resulting in the highest fracture strain of 68.6 % at 5.0 wt% Ag content. The microstructure of Bi-1.5Ag (hypoeutectic alloy) is composed of well-developed dendritic primary Bi phase along with eutectic structure, the microstructure of Bi-2.5Ag (eutectic alloy) is composed of cellular eutectic structure, and the microstructure of Bi-5.0Ag and Bi-7.5Ag (hypereutectic alloy) is composed of primary Ag phase surrounded by a Bi phase and eutectic structure. Except for Bi-2.5Ag alloy, the strain distribution of other alloys is nonuniform. A considerable number of low-angle grain boundaries (LAGBs) appear in the eutectic structure with larger strain. The strain of the primary Bi phase was slight, the Bi twin structure is observed for the first time in Bi-1.5 Ag, which demonstrates excellent uniform plastic deformation capacity. The primary Ag phase causes stress concentration, which has an adverse effect on plastic deformation. The increase of Ag content is not positively correlated with the increase of fracture strain, which is mainly attributable to the size and distribution of primary Ag phase.