The procurement of public construction, which has been selected mainly on the basis of the work experience of a department of public agencies that award construction contracts or those in charge of ordering, has not been executed through an objective selection process considering the construction types or characteristics. Thus, as a preliminary study on developing a model for the selection of contract methods, this study intends to analyze and present the key factors affecting the selection of procurement methods in public construction. Through a literature review on the existing methods, foundational factors were first presented, based on the analysis of these factors, the final influence factors were proposed. As a result, 6 factors contractor's characteristics, the environment of the construction market, relevant organization, the characteristics of a project, costs, and responsibility factors were determined, and 14 sub-factors were selected. The factors presented in this study will be used as base data for developing a decision making support model for the selection of contract methods in public construction.