From 1883 (the late Korean dynasty), South Korea began to use Taiji flag. After the establishment of the Republic of Korea, it continued to be used. 1949, the Korean Ministry of Education officially confirmed the current style of the Korean national flag: the center of the national flag is Tai Chi pattern with eight diagrams around it. According to the official explanation of South Korea, the red in the Taiji diagram represents Yang, the blue represents Yin, and the unity of Yin and Yang represents the balance and harmony of the universe. Fire and water, day and night, darkness and light, construction and destruction, male and female, active and passive, hot and cold, positive and negative, as two major forces in the universe, achieve harmony and balance through mutual opposition.

With the ether as the center, the four hexagrams symbolize the harmony of Yin and Yang, the dry hexagrams represent the sky, the Kun hexagrams represent the earth, the Kan hexagrams represent the moon and water, and the departure hexagrams represent the sun and fire. Each six-pointed star also symbolizes justice, richness, vitality and wisdom. According to South Korea's explanation, the background color of the national flag is white, which symbolizes the purity and love for peace of the Korean people. The whole national flag represents the ideal of the Korean people to develop harmoniously with the universe forever.

The thought of Tai Chi and Eight Diagrams of the Korean flag comes from China's Zhouyi. The principles of harmony, symmetry, balance, circulation and stability represent the profound thinking of the Chinese nation on the universe and life. The Korean Peninsula has been influenced by China culture for a long time, and the Korean flag is a reflection of this influence.

China's Zhouyi and Taoism are quite influential in South Korea. 1882 In August, two envoys of the Lee Dynasty, Park Yongxiao and Yu Jinyun, were ordered to go to Japan for negotiations. At that time, there was no national flag in the Li Dynasty. The two emissaries believe that as a representative of a country, it is impossible without a national flag. After discussion, they decided to adopt the Tai Chi diagram with rich connotation and profound philosophy in Zhouyi as the national flag pattern. So they drew the Artest flag on the boat to Japan. After returning to China, the two reported to the government about drawing the national flag, which was affirmed and praised. The following year, 1883, the Lee Dynasty officially promulgated the flag as the national flag of the Lee Dynasty.

1948, when the Korean government was founded, it was decided to use the Taiji flag as the national flag of South Korea, and in 1949, the production standard was promulgated: the ratio of Taiji flag was 3: 2; White background represents sacred land; Taiji diagram symbolizes the universe, the world and the country composed of a single nation. The circle of Tai Chi in the middle represents the people; The two instruments of Tai Chi are upper red and lower blue, representing yin and yang respectively.