Calcineurin B-like interacting protein kinases (CIPKs) play important roles via environmental stress.However,less is known how to sense the stress in molecular structure conformation level.Here,an OsCIPK7 mutant via TILLING procedure with a point mutation in the kinase domain showed increased chilling tolerance,which could be potentially used in the molecular breeding.We found that this point mutation of OsCIPK7 led to a conformational change in the activation loop of the kinase domain,subsequently with an increase of protein kinase activity,thus conferred an increased tolerance to chilling stress.