The agent's capability to acquire, infer, and store the knowledge of other agents is known as agent modeling. Agent modeling addresses the problem of reasoning about an opponent, which is a critical task in competitive situations, or reasoning about a partner, which is important in situations of cooperation, communication, and to enhance social connections. The modeling information is useful to reason about the agent's intentions, to understand its current behavior, and to predict its future behavior. The objective of this work is to carry out a systematic mapping review of the investigations that address this problem in the last 13 years. As a result, the area was categorized in four dimensions, three wide methods, and identified twelve characteristics on the gathered data. The contribution of each investigation has been studied and offer an analysis of each one, as well as a summary of the use cases where the researchers are applying agent modeling. Finally, open problems in the area that could become future lines of research are identified.