Based on information processing models, cognitive biases occurring in different stages of information processing can lead to anxiety disorders in children. Accordingly, the present study aimed to review these cognitive biases effective in developing and maintaining childhood anxiety and have been studied in various research. This narrative review was conducted through search of Persian and English articles in English databases including Scopus, ScienceDirect, PubMed, and Speinger and Persian Databases including SID, Magiran, Ensani.ir (during 2000-2020)  with related keywords. The result of the search was 78 articles that finally 45 articles were selected to enter the study. The results have identified several types of these cognitive biases including attentional bias, judgment bias, memory bias, and Interpretation bias, reduced Evidence for danger (RED) bias, emotional reasoning, probability bias, and covariation bias. These biases are related to cognitive processes that are distorted and inaccurate and thus trigger maladaptive thoughts and behaviors. Obviously, this biased information processing can easily invoke feelings of fear and anxiety that in turn increase cognitive bias and can reinforce risk and vulnerability for maladaptive schemas. In conclusion, Identifying and understanding these cognitive biases will shed light on the mechanism of the development and maintenance of anxiety in children and can lead to more effective treatments designed to reduce these biases and thereby reduce anxiety in children.