Subjective, physiological, and behavioral responses to potentially stressful situations may be a function of both cognitive appraisal and cognitive beliefs. Beliefs, such as locus of control, has been distinguished in the research literature as critical to psychological well-being and coping with stress. Very few studies have examined the role of beliefs on stress process directly. In present study, the effect of locus of control and stressor type, on cognitive appraisal and physiological responses were directly investigated. The result supported a stress-moderating effect for locus of control especially in active coping situation. Individuals who have internal locus of control showed more benign cognitive appraisals and physiological responses when they were performing arithmetic task. The result indicate that physiological activity must be interpreted in light of the individual characteristics and situational context within which the physiological activity take place.