The ancient star official system in China divided the night sky into three walls and twenty-eight nights. The ancients looked up at the stars overhead in the evening of the vernal equinox near the intersection of Huangchi and Jiaojiao, and divided twenty-eight huts into four sections according to the four directions of southeast, northwest and northwest. Each section corresponds to an elephant, and each section contains seven nights: the bird elephant is in the south, the dragon elephant and the tiger elephant are in the east and west respectively, and the tortoise and snake are hidden under the north horizon. In ancient times, the popular theory of five elements and five colors was that blue, red, yellow, white and black were matched with east, south, middle, west and north respectively, and finally the theory of oriental black dragon, western white tiger, southern suzaku (bird) and northern Xuanwu (tortoise and snake) was formed.
Ancient astronomy in China has its own method of distinguishing and dividing the star regions, which is different from the western method of dividing the zodiac. In ancient astronomy in China, the system of "star officials" similar to western "constellations" was used. The most systematic method was to divide 1464 stars in the sky into "283 officials". In ancient China, the system of "star officials" divided the sky into "three walls and twenty-eight lodges" and other star officials. (The records of star officials in the existing ancient books first appeared in Records of the Historian Tianguan's Biography, and "283 officials" included such star officials as "Three Walls" and "Twenty-eight Accommodations".