Objectives: Previous studies indicate that pre-sleep arousal plays an important role in the etiology of insomnia. Self rating scales, such as the Pre-Sleep Arousal Scale (PSAS), have been developed to measure arousal level prior to sleep. The goal of the current study was to evaluate the psychometric properties of the Chinese version of the PSAS.Measures: The study recruited 194 normal sleepers from local communities and 279 insomnia patients in northern Taiwan. Insomnia patients were diagnosed through a structured interview conducted by a physician or a clinical psychologist specialized in sleep medicine. All subjects completed a package of questionnaires including the Chinese version of Beck Anxiety Inventory (BAI) and PSAS. In addition, 59 of the insomnia patients went through a six-session CBT-I program. After the treatment, the questionnaires were administered again.Results: The results showed that the Chinese version of PSAS had adequate internal consistency with Chronbach's αs range from .80 to .89. In terms of validity, two factors (somatic & cognitive arousal) emerged for the PSAS. Moreover, Chinese version of PSAS showed very good concurrent validity with the BAI. It could effectively discriminate good sleepers from insomnia sufferers, and detect the declines of somatic and cognitive hyperarousal resulted from CBT interventions.Conclusion: In conclusion, the results indicated that the Chinese version of PSAS had good internal consistency and validity. It served as a measure of the hyperarousal in insomnia patients, as well as an outcome measure for evaluating insomnia treatment effects, particularly for those that target hyperarousal.