The present study investigated the composition of negative affect and its function as inhibitory to thought processes such as self-regulation. Negative affect in the present study were composed of anxiety, worry, thought suppression, and fear of negative evaluation. These four factors were selected based on the criteria of negative affect by Hopko, Hunt, and Armento (2005) and Smith and Kirby (2001). Four different scales were used to measure these factors. The factor structure of the negative affect was tested using Confirmatory Factor Analysis. Results showed that all items as indicators were significant and all the four factors of negative affect were significantly related. The inhibitory function of the negative affect on self-regulation was further tested using Structural Equations Modeling. The results showed that as negative affects increase, there was a reduction of 4% variance on self-regulation. The model showing the inhibitory function of negative affect also attained an adequate fit. An appendix presents: Parameter Estimates of the Items of Each Negative Affect Factor. (Contains 1 figure and 2 tables.)