This is a seat with a curved surface shape, people can easily achieve cross legged sitting by it. This seat ware can effectively distribute the force of the buttocks of the human body evenly to the outside of the knee and the thigh. Even if keeping long time this posture, we will not feel tired. The back can feel the support of the caudal vertebrae, increasing the support of the waist. This design is not only a reflection of culture, but also a study of ergonomics.