Background and Purpose: Social anxiety is one of the most common anxiety disorders in childhood that is related to the family system. The purpose of this study was to predict the social anxiety of primary school children based on the emotional regulation difficulties and cognitive flexibility of their mothers.Method: This research is a descriptive study in the form of a correlation design. For this purpose, 120 students (along with their mothers) were selected by multistage cluster sampling method from primary school children from 4th to 6th grades in Arak, Iran. The students were asked to perform the Liebowitz social anxiety scale for children and adolescents (Masia-Warner2003), , and for their mothers, the difficulties in emotion regulation scale (Gratz & Roemer, 2004) and cognitive flexibility scale (Dennis & Vanderwall, 2010) were performed. The collected data were analyzed by pearson correlation coefficient and multiple simultaneous regressions.Results: The findings indicated that difficulties in emotion regulation and cognitive flexibility of mothers predict 57% of variance of social anxiety in children (F= 21/38, p< 0.001). Also, the subscales of difficulties in engaging in goal-directed behavior and limited access to emotion regulation strategies had a significant role in predicting of this variable with a beta coefficient of 0.335 and 0.325, respectivelyConclusion: The difficulty in emotion regulation of mothers can be related to social anxiety in their children, and as mothers have more problems in their emotional regulation, children will also show more problems in social interactions such as social anxiety; therefore, the empowerment of mothers for better manage and regulate emotional problems leads to less social anxiety in children.