The present study developed and evaluated the Automatic Thoughts List following Dilatory Behavior (ATL-DB) to explore the mediation hypothesis and the content-specificity hypothesis about the automatic thoughts with trait procrastination and emotions. In Study 1, data from 113 Japanese college students were used to choose 22 items to construct the ATL-DB. Two factors were indentified, I. Criticism of Self and Behavior, II. Difficulty in Achievement. These factors had high degrees of internal consistency and had positive correlations to trait procrastination. In Study 2, the relationships among trait procrastination, the automatic thoughts, depression, and anxiety were examined in 261 college students by using Structural Equation Modeling. The results showed that the influence of trait procrastination on depression was mainly mediated through Criticism of Self and Behavior only, while the influence of trait procrastination to anxiety was mediated through Criticism of Self and Behavior and Difficulty in Achievement. Therefore, the mediation hypothesis was supported and the content-specificity hypothesis was partially supported.