The subjective experience in 43 Chinese adults with chronic primary insomnia was assessed using focus groups and insomnia experience diaries. Participants recruited from the community and a sleep clinic were diagnosed with DSM-IV-TR insomnia disorder and had sleep difficulties on 3 or more nights per week for at least 6 months. Six focus groups, of 6-8 participants each, were conducted; it was stopped as thematic saturation emerged in the last 2 groups. Using grounded theory approach, we identified 4 themes and 16 subthemes, covering beliefs about the nature and treatment of insomnia, behavioral responses to insomnia, cognitive-emotional and physiological arousal, and emotional experiences associated with insomnia. The findings are in general compatible with qualitative studies in the West, but some subthemes are influenced by Chinese cultural beliefs and values, in particular, use of the traditional Chinese medicine concept, being modest in sleep expectation, and a letting go attitude. Strategies for cultural adaptation of cognitive-behavioral therapy for insomnia in a Chinese society using patients' subjective experience are discussed.