This study examines the relationship between the equinoxes and solstices and the directional scheme in traditional ritual. For this purpose, the study focuses on “Yao dian” 堯典(Canon of Yao) to understand the principles of directional assignments in Confucian rituals from the natural science perspective. The four directions in “Yao dian” are related to the equinoctial and solstitial points in the sun''s movement cycle are shown by the tasks and the places assigned to the Xi 羲and the He 和families. The tasks and the places assigned to the both families also correlatewith their family and given names, and yin-yang cosmology plays a key role in identifying these correlations. Moreover, the equinoxes and solstices marked both seasonal divisions (jieqi 節氣) in time and cardinal points in space, specifically the four directions corresponding to zi 子, wu 午, mao 卯, and you 酉among the 12 Earthly Branches (shier di zhi 十二地支). These directions were arranged in a circle reflecting the sun''s movement cycle, and constituted a directional framework that comprised yearly cyclical changes in both time and space. The directional scheme in traditional ritual regards the north as the topmost position, and the Clan Law (zongfa 宗法) from the Zhou dynasty onward took this as a basic principle of assignment in regard to the order of ranks. Accordingly, it places the summer solstice in the upper part of the celestial sphere, and the winter solstice in the lower part, and thus the positioning of the south and north directions accords with the sun''s declination at summer and winter solstices. The east and west directions pertaining to the spring and fall equinoxes, however, can also be related to its diurnal motion from east to west. Residing in these four directions, the Xi and the He familieswere taskedwith correctly determining the equinox and solstice days by observing the lengths of day and night and the stars in the sky. Their celestial observations were crucial to establishing the annual calendar, which was an important part of the sage king’s government. [Article in Chinese]