The dream is a well-known experience in the routine life. It is necessary to consider the dream to modality of diagnosis because many evidences that the dream represents the physiologic and pathologic changes in the human have been proved in recent days. The oneironosus(病夢) was caused by three factors, which are the external stresses of the body, malfunction of Jang-Bu(臟腑) and irregular of Yin-Yang(陰陽) and Gi-blood(氣血). The oneironosus(病夢) reflects the location, characteristics, progression and prognosis of the disease. In addition, it predicts the development of disease. The principle of treatment for the oneironosus(病夢) is making an effort for the stabilization of mind by eradicating the internal and external factors that make the spirit(神) been unstable.