The Korean practice known as bulbokjang(佛腹藏), which involves enshrining artifacts in cavities within Buddhist statues differs from equivalent practices in China and Japan, having developed a unique local culture of its own. The Buddhist text Josang gyeong(造像經) was hugely inf luential in the development of this unique form of bulbokjang. Josang gyeong gives specific descriptions of bulbokjang as a Buddhist ritual, based on texts such as Zhufo pusa fuzang tan yishi(諸佛菩薩腹藏壇儀式), Miaojixiang dajiaowang jing(妙吉祥大敎王經) and San xidi tanshi(三悉地 檀釋), which focus on enshrined items and ceremonies. These scriptures show connections to the Mahāvairocana Sūtra(大日經) and Vajraśeka Sūtra(金剛頂經), which formed the basis of middle- period Esoteric Buddhism, and late-period Esoteric sūtras such as Tuoluoni ji jing (陀羅尼集經), Miaojixiang dajiaowang jing, and Sanzhong xidi sanbu yigui(三種悉地三部儀軌). This study therefore aims to examine the meaning and ideology behind palyeoptong(八葉筒) and huryeongtong (喉鈴筒), and the five direction-related Five Buddhas(五佛) and Five Wisdoms(五智), all important elements in Korean bulbokjang, within the context of their relationship to Esoteric Buddhist scriptures. The Josang gyeong, in which all items mentioned are based on the five directions, contains elements such as the obobyeong (五寶甁), ogok(五穀), o’yak(五藥), obo(五寶), ohyang(五香) and ohwang(五黃). These are forms of the Five Buddhas, related to the Womb Realm Mandala of the Mahāvairocana Sūtra and the Diamond Realm Mandala of the Vajraśekhara Sūtra. The wisdom of ✽ Sudeoksa Temple Museum the Five Buddhas, in conjunction with the obang’gyeong(五方鏡), oryun jongja(五輪種子), and jinsim jongja(眞心種子), which do not appear in the Miaojixiang dajiaowang jing, gain extended meaning through the obobyeong and osaeksil(五色絲) to become ohyeong(五形), oja(五字) and osaek(五色). It is therefore highly likely that not only the Womb Realm and Diamond Realm Mandalas but also Sanzhong xidi sanbu yigui had reached Korea before the introduction of Miaojixiang dajiaowang jing during the Goryeo period. This tells us that the ideological background to Josang gyeong was a continuation of mid-period Esoteric Buddhism from China and, subsequently, late-period Esoteric Buddhism, which continued to develop in a style similar to that of China. The fact that the forms of bulbokjang changed from Goryeo to Joseon in conjunction with the appearance of huryeongtong with huhyeol(喉穴) during the early Joseon period indicates a change in the esoteric nature of bulbokjang at this time. This change gave shape to the key differences and similarities between Goryeo palyeongtong and Joseon huryeongtong. The formation of the central eight-petal hall depicted in Womb Realm mandala and the Five Buddhas were transformed and accommodated in the Goryeo period in the forms of palyeongtong and obobyeong. The pipe-like huhyeol of Joseon-period huryeongtong represents an expression of the universe in the sounds of the Diamond Realm mandala; this corresponds to the period from which huryeong(喉鈴) have not been discovered inside Buddha statues, allowing us to surmise that the huhyeol was introduced as a replacement for the huryeong. In other words, it can be said that the huryeongtong represents a single, complete dharma by providing a connection between the obobyeong inside it and the outside, via the osaeksil and the huhyeol. The characteristics of Esoteric Buddhism are visible in all aspects of Korean bulbokjang, from enshrined items to rites and imbued significance. In other words, it appears that Esoteric Buddhist mandala-related elements based on the principle of the five directions were incorporated during the Goryeo and Joseon periods to produce bulbokjang with unique Korean characteristics.