天龍八部是佛教藝術史上一種別具特色的重要題材。這種題材在中國佛教藝術史上盛行於唐朝和五代，現存的天龍八部群像以四川石窟和敦煌石窟最多。漢譯佛經中有一種普遍共識，認為印度神劃分八類：天Deva、龍Nāga、夜叉Yakṣa、乾闥婆Gandharva、阿修羅Asura、迦樓羅Garuḍa、緊那羅Kinnara、摩睺羅伽Mahoraga，又稱「八部眾」或「八部鬼神」。於是佛教藝術中，天龍八部被創造出來，以群體組合形式代表所有護法神這一整體。然而，天龍八部群像組合在印度、中亞、東南亞都沒有，是中國人的獨創。今天的印度教也沒有這種神分八類的概念。天龍八部這個概念到底是怎麼回事？這八類神在印度又是什麼含義什麼形像？過去學界有日本和中國學者對天龍八部群像整理研究，依據漢譯佛經對天龍八部群像中的個體進行識別，但沒有關注天龍八部這種分類法和八類神的印度原意，以及中文文獻的釋義和中國的圖像與印度之間的巨大斷層。本文旨在澄清天龍八部這一概念，並考察探源這一群像組合中的各神的由來。本文提出天龍八部的說法與印度迦葉波（Kaśyapa）的神話有關，大約四世紀末五世紀初的時候隨佛經傳入中國。天龍八部群像組合方式是中國人的發明，天龍八部各類神像，都與印度的差別巨大，反映了中國人對於印度佛教眾神的理解與再解讀。此外對八部中的每一類神怪，本文都就其概念和圖像進行了更進一步的考證。

Tianlong Babu (天龍八部, God and Dragon of Eight Types) is an unique and important subject of Buddhist art. It was prevalent in China during the Tang (618-907) and Five Dynasties (907-979). The extant images are mostly preserved in caves in Sichuan and Dunhuang. It is commonly described in the Buddhist texts translated into Chinese that the Indian deities are classified into eight types-deva, nāga, yakṣa, gandharva, asura, garuḍa, kinnara, and mahoraga. They are also referred to as Babuzong (八部眾) or Babu Guishen (八部鬼神). Accordingly, the image of Tianlong Babu was created as a group to represent all Buddhist protective deities as a whole. However, the image of the Tianlong Babu group is absent India, Central Asia, and Southeast Asia. It is a Chinese creation. In Hinduism today, there is no such concept that deities are consist of eight types. Indeed, what is the problem with the Tianlong Babu concept? What are the appearances and origins of the individual deities in Tianlong Babu? In the past, Japanese and Chinese scholars have done basic survey on Tianlong Babu group images and identified the deities in the group with the references of Buddhist texts. However, no one has paid attention to the eight-type classification and its Indian origin, as well as the huge gap among images, textual descriptions and their prototype in Indian art. In this paper, I propose that the Tianlong Babu concept is associated with the Kaśyapa legend and was transmitted into China around the end of the fourth and early fifth centuries with Buddhist text. Grouping Tianlong Babu together is a Chinese innovation. Iconographies of the deities in Tianlong Babu are very different from their Indian origins. They reflect the Chinese understanding and reinterpretations of the Indian deities. In addition, this paper also studies the iconography of each type of the deities in this group, the textual sources, and the possible counterparts in India and Central Asia.