In construction projects, the different interests and objects of stakeholders can result in increased occurrences of conflict, which can bring negative effects or even project termination. In particular, understanding the causes and finding a solution get more difficult because of the larger and more complex projects. Thus, quantitative research should be conducted to find conflict alternatives. This study aims to find optimal alternative combinations for conflict resolution in public projects. To understand level of conflict and effect of conflict alternatives, the survey was conducted in three points of view: 1) economic; 2) social; and 3) environmental. After survey, the optimization process consists of two steps. First, weights of conflict factors are estimated through regression analysis. Second, multi-object functions which are each economic impact, social impact, environmental impact are optimized. For multi-objective optimization, optimal alternative combinations could be deducted and results present how alternatives affect to conflict level. Although there are some limitations, this result is significant in that it has found an optimal alternative considering three impacts in order to select a combination of alternatives for conflict resolution.