nsomnia is an individual's subjective perception of sleep poorly. Everyone will possibly experience insomnia in his/her life. Stresses, illnesses or diseases, environmental factors, and emotional problems all can lead to insomnia. Walker and Avant (1995) proposed a concept analysis method to identify the definition and defined characteristics of insomnia. In this article, the authors followed their methods to present examples of insomnia, analyze antecedents and consequences, and provide empirical referents. This article can improve the nurse staff's understanding about the concept of insomnia, skillful usage in their clinical practice, and help of the patients to solve their insomnia problem.