The impact of moral beliefs on individuals' moral judgments, particularly within the framework of contrasting cultural values such as collectivism and individualism, continues to be a subject of interest. This research delves into whether individuals with distinct values display differences in moral beliefs, with a specific focus on selflessness. Through experiment 1 and 2, we scrutinize the moral judgments of individuals with diverse values concerning pro-social behaviors driven by selflessness and in-group favoritism. Experiment 3 investigates the underlying mechanisms by examining reward expectations. The findings from experiments 1 and 2 indicate that collectivists exhibit significantly higher moral judgment levels for selfless pro-social behaviors compared to individualists, highlighting a disparity in moral beliefs between the two value systems. Experimental 2 also found that collectivists' moral judgments rose and fell as rescuers' selflessness increased or decreased. However, individualist moral judgment did not change significantly with behavioral selflessness. The results reveal that collectivists hold higher reward expectations for selfless behavior, which contributes to their heightened moral judgment of selfless behavior. While it may be assumed that collectivists' moral beliefs would be dominated by in-group preferences, aligning with the conceptual in-group preference of collectivism, this study unexpectedly found evidence of collectivists' pursuit of selflessness in their moral beliefs. These findings offer initial evidence of distinct patterns of moral beliefs associated with collectivism and individualism, shedding light on potential reasons that lead collectivists to possess stronger moral beliefs about selflessness.