This study conducted a comparative analysis of Chinese subsidiaries of Korean, Japanese, and Taiwanese firms, examining how localization strategy dimensions differ according to subsidiaries' investment motives and firm size, and what factors—including localization strategy variables—influence subsidiary investment performance. Examining the analysis results, for Korean subsidiaries, localization of value-added activities showed higher localization levels for domestically-oriented subsidiaries than for export-oriented subsidiaries in both large and small-medium enterprises, and by firm size, large enterprises exhibited higher levels than small-medium enterprises. Regarding the localization of management practices, large enterprises showed higher localization levels than small-medium enterprises. However, the localization level of decision-making authority according to investment motive was higher for export-oriented subsidiaries than for domestically-oriented subsidiaries. For Taiwanese subsidiaries, the localization of value-added activities showed significant differences by firm size, and the localization of management practices showed significant differences in both firm size and investment motive. However, the localization level of management practices was higher for small-medium enterprises than for large enterprises, and also higher for export-oriented subsidiaries than for domestically-oriented subsidiaries. The localization level of value-added activities was significantly higher for small-medium enterprises than for large enterprises. Meanwhile, the analysis of Japanese subsidiaries did not produce significant results in any case, which appears to be due to the small number of firms analyzed. Next, examining the significant factors influencing Chinese subsidiary investment performance by investment motive, for Korean subsidiaries, maintaining harmonious local labor-management relations was found to be important for both export-oriented and domestically-oriented subsidiaries. Additionally, for domestically-oriented subsidiaries, superior production capability and the parent company's brand awareness were analyzed as influencing investment performance, and compared to export-oriented subsidiaries, domestically-oriented subsidiaries with longer years of operation in China showed more satisfactory investment performance. The finding that harmonious local labor-management relations, superior production capability, and the parent company's brand awareness are key variables influencing subsidiary investment performance was equally observed for Japanese subsidiaries; however, for Japanese subsidiaries, the local labor-management relations variable was found to be significant only for export-oriented subsidiaries. Meanwhile, in this study, localization strategy dimension variables were found not to influence the investment performance of Korean subsidiaries. For Japanese subsidiaries, in the case of small-medium enterprises where statistical analysis was feasible, firms with lower levels of management practice localization were found to achieve higher investment performance. In contrast, for Taiwanese subsidiaries, small-medium enterprises with lower levels of value-added activity localization and higher levels of management practice and decision-making authority localization showed better investment performance.