The theme of this issue quite interestingly recalls the deity Youchao, who was the building inventor in our Chinese legend. In remote ancient times, Youchao led his people to build nests, in order to protect themselves from birds and beasts, insects and snakes, as well as dampness. The safe and comfortable nests were to become their home. And among all nests, tree house was the earliest-built. While, tree house in the Southest Asia (including the southern area of China) was no rare thing in all ages, for instance, the classical Ganlan styled buildings. From the Youchao legend, we can assume the influence of the southern area in early Chinese civilization, or we can suppose that the contemporary climate in the Yellow River area resembles today’s subtropical climate, nurturing dense forests. Nowadays, cave is the most commonly seen dwelling in the Yellow River area, which is another dwelling form passed down from the sprout period of caves. Tree house, nowadays, provides us with an opportunity to experience the coexistence with trees, so that we can turn away from lifeless building materials to leaves, fruits and nests. Finding one’s right position and “living poetically” (advocated by Hoederlin), is exactly what tree house aims at. Regretfully I have not been to any of the tree houses issued here, but I thought the tree house I formerly visited in Tainan really great. And this spring, when I went to Awa Mountain in Yunnan province, I saw a tree kiosk built by the villagers. It towered aloft in the thick shade, simple but very impressive. It has no designers, but coexists perfectly with the tree. Tourists can climb up and look around with only 5 RMB.