• This paper reviews the mechanisms of SO 2 & H 2 O poisoning of low temperature SCR catalysts. • The strategies for improving the resistance of SCR catalysts to SO 2 & H 2 O poisoning are summarized and discussed. • Application of theoretical calculations in the development of low-temperature SCR catalysts with a strong resistance to poisoning is also included. • Based on the problems detailed in this review, the challenges and the emphasis for future research in this area are also proposed. Low temperature selective catalytic reduction (SCR) is an efficient and promising technology to transform NO x into N 2 from flue gases, which has broad application prospects. However, the vulnerability of low temperature DeNO x catalysts to poisoning by SO 2 and H 2 O restricts their industrial application. Therefore, it is vitally important to develop new low temperature DeNO x catalysts that resist poisoning. This paper reviews the mechanisms of SO 2 & H 2 O poisoning of low temperature SCR catalysts, the strategies for improving the resistance of low temperature SCR catalysts to SO 2 & H 2 O poisoning, application of theoretical calculations in the development of SO 2 & H 2 O resistant low temperature SCR catalysts as well as novel ideas for developing poisoning resistant low temperature SCR catalysts. Moreover, the studies dealing with the regeneration of low temperature DeNO x catalysts are also included. Based on the problems detailed in this review, the challenges and the emphasis for future research in this area are also proposed. We believe that this review will provide an excellent foundation and good guidance for the future design and the development of improved SO 2 & H 2 O-tolerant low temperature DeNO x catalysts. [ABSTRACT FROM AUTHOR]