The Mahāratnakūṭa Sūtra (Sanskrit; traditional Chinese: 大寶積經; simplified Chinese: 大宝积经; pinyin: dàbǎojī jīng, Tib. dam-chos dkon-mchog-brtsegs-pa) is an ancient collection of Mahāyāna Buddhist sūtras. It is also known simply as Ratnakūṭa Sūtra (寶積經), literally the Sutra of the Heap of Jewels in Sanskrit (kūṭa means ‘accumulation’ or ‘heap’).
The Mahāratnakūṭa Sūtra contains 49 texts of varying length, which are termed "assemblies" by tradition. This text was brought to China and translated by Bodhiruci in the 6th century. Bodhiruci translated some of the texts, and included others which had been previously translated. This collection includes the Śrīmālādevī Siṃhanāda Sūtra, the Longer Sukhāvatī-vyūha Sutra, the Akṣobhya-vyūha Sūtra, a long text called the Bodhisattvapiṭaka, and others.
The Ratnakūṭa collection totals 49 Mahāyāna sūtras, divided into 120 fascicles in the Chinese translation. Garma Chang, who has translated a number of sūtras from the Mahāratnakūṭa from Chinese into English, summarizes the breadth and variety of texts contained in this collection:
We have found this work to contain a broad coverage of various subjects. The topics discussed range from the monastic precepts (Vinaya) to intuitive wisdom (prajñā), from good deportment to the manifestation of the Tathāgata's light, from illusion (māyā) to ingenuity (upāya) to the nature of consciousness and the Pure Land practice. It can perhaps be called a small encyclopedia of Mahāyāna Buddhism, which should be useful to general readers as well as to scholars.
In the Taishō Tripiṭaka in volumes 11 and 12a, the Mahāratnakūṭa is the text numbered 310, and texts numbered 311 through 373 are various other translations of some of the sutras contained in the Mahāratnakūṭa.
According to the Nikāyasaṅgraha (a Theravādin text), the Ratnakūṭa Sūtra was composed by the "Andhakas", meaning the Mahāsāṃghika Caitika schools of the Āndhra region. The texts of the sutra seem to have been collected over a number of centuries, and their varying subject matter is suggestive of historical transitions between major eras of Buddhist thought. The collection may have developed from a "Bodhisattva pitaka" attributed to some of the early Mahayana schools.