The Four Directional Guardians (四天王) that protect Buddhist Law were carved in relief on the sides of pagodas, architectural structures or were made into sculptures. And in Buddhist paintings such as the Assembly of Sakyamuni Preaching at Vulture Peak (靈山會相圖), Paradise of the Amitabha Buddha (阿彌陀佛繪圖), Kshitigarbha and Ten Kings of Hell (地藏十王圖), and the Illustration of Descended Maitreya Buddha Preaching (彌勒下生變相圖), they appear either as sinjung (神衆, literally “host of divine beings”) who protect the Buddhist assembly of the Dharma preaching, or as cheonsin (天神, heavenly gods) who listen to the sermon on the Dharma. The Four Directional Guardians continued to appear on numerous Buddhist monuments and paintings since the Unified Silla dynasty until today, but also underwent some iconographic changes. While one can effectively identify the Four Directional Guardians in threedimensional space in accordance with the four directions to which they belong, a different rule of arrangement should be applied in the depiction on two-dimensional plane like a painting. In painting, the guardians have always been arranged in an established format except during the period of the late Goryeo and early Joseon dynasties. Considering that the format, in which the images of the east and west, and those of the north and south were symmetrically positioned on either side of the main Buddha, is a standard one, the principles of the arrangement can be categorized into two types. The first type-A is which the guardian of the north is turned toward the left side, and type-B is which the guardian of the north is turned toward the right side. The former type-A arrangement of the Four Directional Guardians was applied in the Unified Silla until the late Goryeo period, while the latter type-B appeared in the late Goryeo and early Joseon dynasties and is still continued until present time. It is worth noting, as aforementioned, that the arrangement of the Four Directional Guardians underwent some changes in the late Goryeo and early Joseon dynasties, and it is surmised that the cause of the change was due to the introduction of woodblock prints of Saddharmapundarika Sutra in the late Goryeo period from the Hangzhou region of the Southern Song dynasty. Most of the depictions of the Four Directional Guardians in the late Goryeo period follow the traditional style, suited in armor, holding attributes such as a pagoda, a sword, bows, etc., after the iconography established during the Tang and Song dynasties. However, a few other types are also found to have been influenced by the iconography of the Four Directional Guardians of the Tibetan Buddhism. The Four Directional Guardians on the gilt-bronze portable shrine in the National Museum of Korea, and on the pagoda of Gyeongcheonsa temple dating from the late Goryeo, and those on the pagoda of the Wongaksa temple of early Joseon feature traditional elements of Goryeo’s Four Directional Guardians, but some changes are noticed in the posture of holding the sword in a slanted position and in a guardian playing a lute. These iconographic changes find their prototypes in the images of the Four Directional Guardians of Tibetan Buddhist art, and I believe that it was introduced to Goryeo along with the exchanges between the Mongol Yuan and Goryeo Courts during the period of the Yuan interference in the Goryeo. The more definite source of the iconography of the Tibetan Buddhist iconography of the Four Directional Guardians is the imperial woodblock prints of the early Ming dynasty. Since it is recorded in history that the Ming Emperor ordered a hundred books of Songs Adoring Various Buddhist Images (諸佛如來菩薩名稱歌曲) to be presenedt to Goryeo Court in 1417, and also the existence of a woodblock version of Saddharmapundarika Sutra commissioned by Lady Shin, the wife of the Royal Prince Gwangpyeong in 1459, I came to understand that, the standard form of iconography of the Four Directional Guardians in Tibetan Buddhist style were newly introduced to Goryeo Buddhist society. As it has been observed, the attributes and arrangement of Four Directional Guardians in the style of Tibetan Buddhist iconography in the late Goryeo and early Joseon dynasties are also found in the Buddhist paintings of the sixteenth century Joseon. They later formed the typical type of iconography of the Four Directional Guardians in the late Joseon dynasty that continues until today. The Joseon dynasty, however, was more inclined toward Confucianism and governed according to Confucian philosophy, so Buddhism received less external influence. Therefore, they were rendered in uniquely Joseon style in which the personal style of monk painters and their new interpretations of iconographies were much more freely reflected.