The aim of this research was to study the relationship of emotional regulation, Meta cognitive and optimism with test anxiety of complementary education students of Khouzestan research and science center. The sample of this research consisted of 440 students selected through the stratified random sampling form all students of Khouzestan Research and Science University. The emotional regulation inventory, cognitive state inventory, optimism scale (ASQ) and test anxiety inventory were used for collecting data. Present research was from correlation type, and data were analyzed by using Pearson correlation and multiple regression at the meaningful level (p<0.0001). Results showed that there was meaningful positive relationship between emotional regulation and test anxiety. However, there was meaningful negative relationship between Meta cognitive and test anxiety and also optimism and test anxiety. Findings also showed that there were multiple relationships between emotional regulation, meta cognitive and optimism with test anxiety. Also, regression analysis showed that emotional regulation is best predictor of test anxiety.