Fairness is one of the principles people use for decision-making. Many factors can change fairness perception. In Dr. Tam's emotional model, emotion serves as an internal feedback to assess the disparity between the internal predicted outcomes and the actual outcomes in reality (Tam 2014). Toward the goal of understanding the relationship between emotional status and fairness perception, this study will use the ultimatum game to determine how subjective fairness change under the influence of emotional response of previous situations. Functional near-infrared spectroscopy will be used to monitor the cortical activation during the experiment. It is important to understand how subjective fairness changes because it is one of the principles that influence the social decision-making.