This study was conducted to investigate the effect of relationship and service marketing on the brand interest and behaviors among Korean and Chinese active senior consumers and whether this effect differed between the two groups. A survey was conducted by having participants complete questionnaires administered by a research firm. For empirical analysis, frequency, EFA, CFA, SEM, the metric invariance test, and multiple-group comparison analysis were performed. The analysis results revealed that relationship marketing positively affected both brand interest and consumer behavior. Although service marketing positively affected brand interest, it did not have a significant effect on consumer behavior. In other words, brand interest positively affected consumer behavior through relationship and service marketing. Multiple-group comparison analysis demonstrated that no difference existed between Korean and Chinese active consumers in terms of how relationship marketing affected their brand interest, but a difference existed in how it affected their behavior. Service marketing had a greater influence on Chinese active senior consumers’ brand interest than on Korean active senior consumers. However no difference existed between the two groups with respect to how service marketing affected their behaviors. Finally, brand interest had a positive effect only on Korean active senior consumers’ behavior through relationship and service marketing, but not on Chinese active senior consumers. In conclusion, relationship and service marketing should be used to enhance the brand interest among Korean active senior consumers, and business activities should be planned by building relationships with Chinese active senior consumers to affect their behavior.