Feedback-based learning is a process in which decisions are made based on the previous feedback. This learning process is influenced by acute stress. However, different laboratory stressors elicit different physiological response patterns, which may influence feedback processing differently. Moreover, individual differences in stress reactivity may be associated with reward sensitivity. Therefore, the present study investigated the effects of psychosocial and physical stress on feedback-based learning. The relationship between stress reactivity and reward sensitivity was also examined. Ninety-two college-aged subjects were assigned into the mental arithmetic (MA) task or the cold pressor task (CPT) group. All subjects performed a feedback-based learning task prior to and after the stressor. Cardiovascular reactions, stress experiences, and learning outcomes were recorded during tasks. Trait differences in behavioral inhibition and activation (BIS/BAS) were also measured. Results indicated different patterns of cardiovascular reactions to the MA and CPT. Learning outcomes were differentially influenced by the MA and CPT. Moreover, subjective stress scores were negatively correlated with the learning rate in the pre-stress learning task. Additionally, BAS Drive subscale score was related to the processing of positive feedback. The results suggested that physical and psychosocial stress influence learning through distinct neural mechanisms and psychological processes. Motivational processes underlie the relationship between stress reactivity and reward sensitivity. This study extended research on stress and learning, and the findings have applied implications in various areas. / Ph. D. / People learn to make decisions based on their previous experiences. These processes are influenced by a wide range of non-learning factors, such as stress. Different types of stress may influence learning and decision-making differently. The present study examined the effects of physical and psychosocial stress on a feedback-based learning task. A cold pressor task and a mental arithmetic task were used to induce physical and psychosocial stress, respectively. The parameters that reflect learning processes and outcomes were calculated by using the standard action-value learning algorithm. Physiological measures, including electrocardiograph, respiration, and blood pressure, were recorded. Individual differences in motivation were measured by self-report questionnaires. The results showed that 1) physical and psychosocial stress induced different patterns of stress response; 2) the effects of the two types of stress on learning parameters and performance were different; 3) blood pressure was related to the effect of stress on learning; 4) individual differences in motivation was also related to feedback-based learning. Overall, the present results demonstrated the differences between the effects of the two types of stress, and contribute to the literature of learning and stress. These findings will guide future studies in this area and have applied implications in various areas.