It is widely insisted that irrational cognitions play the role of constructing stress. The present study made a distinction between irrational cognitions and irrational cognitive strategies which generate the former, and examined irrational cognitive strategies in depth. Firstly the present study classified irrational strategies into 4 basic irrational strategies, black-and-white thinking, overgeneralization, magnification-minimization, and mind-reading. It was suggested that each basic irrational cognitive strategy plays the role of constructing both stress and well-being. The present study discussed the reasons why irrational cognitive strategies continue to be used in everyday information processing in spite of playing the role of constructing stress. Lastly the present study also discussed the merits of elaborate comprehension of irrational cognitive strategies in understanding and management of stress.