Integrating a relational perspective and Conservation of Resources (COR) theory, the present research intends to examine how LMX ambivalence reduces task performance by depleting the relational energy. Moreover, this research examines exchange ideology as a relational moderator in the relationship between LMX ambivalence on task performance via relational energy. Employing a sample of 163 supervisor-subordinate dyads, we carried out a survey in Republic of Korea army. Consistent with our hypotheses, our results demonstrated the deleterious impact of LMX ambivalence on task performance via relational energy. Most significantly, our findings showed that this mediated relationship is contingent on the level of exchange ideology. The negative influence of LMX ambivalence on task performance via relational energy was strengthened when exchange ideology is high. Theoretical and practical implications are discussed.