Studies on wettability control with liquid sodium have been conducted via many experiments and theoretical calculations. However, experiments using liquid sodium are challenging because of the high chemical reactivity of liquid sodium. Hence, we plan to perform experiments using a low melting temperature alloy, which is easy to use in air. In this study, the electronic structure of the interface between the substrate metal and the liquid metal was calculated using the molecular orbital method to understand the wettability of pure metal with the low melting temperature alloy. Results showed that the kind of liquid metal affected the atomic interaction at the interface. We obtained some atomic bonds representing a feature of the interface in order to understand the wettability by experiments.