Collective effort to enhance affective capital plays a unique role in promoting people's strength and vitality in work environments. This research was carried out with the aim of determining the relationship between affective-collective investment and conflict resolution efficacy with considering the mediating role of affective capital and sources of conflict resolution efficacy. In a correlation design based on structural equation modeling, 194 employees of Allas Milk Factory in Isfahan, trough convenience sampling participated in this study. The participants responded to the Affective-Collective Investment Questionnaire (1397/2018), Affective Capital Questionnaire (1395/2016), Conflict Resolution Efficacy Questionnaire (2000), and Sources of Conflict Resolution Efficacy Questionnaire (2007). Results revealed that there is a positive significant relationship between affective-collective investment with affective capital, conflict resolution efficacy and sources of conflict resolution efficacy. Results of bootstrap test and structural equation modeling indicated that affective capital and sources of conflict resolution efficacy are complete mediators on the relationship between affective-collective investment and conflict resolution efficacy. It seems that, through the strengthening of affective- collective investment, it is possible to create the context for the promotion of affective capital and sources of conflict resolution efficacy and then the conflict resolution efficacy in the workplace.