The Bagua (Chinese:pinyin: bā guà; Wade-Giles: pa kua; literally "eight symbols") are eight diagrams used in Taoist cosmology to represent a range of interrelated concepts. Each consists of three lines, each either "broken" or "unbroken," representing a yin line or a yang line, respectively. Due to their tripartite structure, they are often referred to as "trigrams" in English.

The trigrams are related to Taiji philosophy and the Wu Xing. The ancient Chinese classic I Ching consists of the 64 pairs of trigrams (called "hexagrams") and commentary on them. The interrelationships among the trigrams are represented in two arrangements, the Primordial, "Earlier Heaven" or "Fuxi" bagua, and the Manifested , "Later Heaven," or "King Wen" bagua. The trigrams have correspondences in astronomy, astrology, geography, geomancy, anatomy, the family, and elsewhere.

The eight trigrams are: Qian, "Heaven;" Xun, "Wind;" Kan, "Water;" Gen, "Mountain;" Kun, "Earth," Zhen "Thunder," Li, "Fire;" and Dui, "Lake."

The history of Baguazhang as an internal form of martial arts is unclear. The most acceptable theory suggests that Dong (T’ung) Hai-ch'uan (1798-1879) learned Bagua from a Daoist named Dong Menglin of Jinhua Mountain in Anhui Province. After rising in fame in Bejing (Peking) Dong (Tung) was challenged by Kuo Yen-Shen of Hsing-i ch’uan both were equally matched and stalemate resulted. A pact between these two masters ensured that their future students were to be instructed in both internal styles. Notable students include Yin Fu, Ch’eng T’ing-hua, Ma Wei-chi, Liu Feng -ch’uan and Shih Liu