Moral discourse embodies interpersonal communication, social relations, responsibilities, and obligations and serves as a reasoning and lecturing tool during judicial activities. As moral imperatives are ingrained in the culture that is instilled into individuals, this study develops an analytical model for identity construction in courtroom moral narratives. The study draws eclectically on the Discourse-Historical Approach in Critical Discourse Studies, positioning theory, and proximization theory. It does so by investigating themes, discursive strategies, linguistic realizations, and identity categories in 10 trials, five selected from court sources in China and five from sources in the United States. Through exploring and interpreting historical and cultural backgrounds, participant identity construction was analyzed and differences between the two countries, with their different legal cultures, were illustrated. Contrasting the moral discourse differences in Chinese and American courtrooms, this study illuminates the complementary use of moral discourse in both courtrooms.