The Shurangama or Śūraṅgama mantra is a dhāraṇī or long mantra of Buddhist practice in East Asia. Although relatively unknown in modern Tibet, there are several Śūraṅgama Mantra texts in the Tibetan Buddhist canon. It has strong associations with the Chinese Chan Buddhist tradition.
The mantra was, according to the opening chapter of the Śūraṅgama Sūtra, historically transmitted by Gautama Buddha to Manjushri to protect Ananda before he had become an arhat. It was again spoken by the Buddha before an assembly of monastic and lay adherents.
Like the popular six-syllable mantra "om mani padme hum" and the Nīlakaṇṭha Dhāraṇī, the Śūraṅgama mantra is synonymous with practices of Avalokiteśvara, an important bodhisattva in both East Asian Buddhism and Tibetan Buddhism. The Śūraṅgama Mantra also extensively references Buddhist deities such as the bodhisattvas Manjushri, Mahākāla, Sitatapatra, Vajrapani and the Five Tathagatas, especially Bhaisajyaguru. It is often used for protection or purification, as it is often recited as part of the daily morning session in monasteries.
Within the Śūraṅgama Sūtra , the Sanskrit incantation (variously referred to as dhāraṇī or mantra) contained therein, is known as the Sitātapatroṣṇīṣa dhāraṇī, The "Śūraṅgama mantra" (Chinese: 楞嚴咒) is well-known and popularly chanted in East Asian Buddhism, where it is very much related to the practice of the "White Parasol Dhāraṇī" (Chinese: 大白傘蓋陀羅尼). In Tibetan Buddhism, it is the "White Umbrella" (Wylie: gdugs dkar)..
The Śūraṅgama Sūtra (Sanskrit: शूरङ्गम सूत्र; traditional Chinese: 大佛頂首楞嚴經) (Taisho 945) is a Mahayana Buddhist sutra that has been especially influential in Chan Buddhism. The general doctrinal outlook of the Śūraṅgama Sūtra is that of esoteric Buddhism and Buddha-nature, with some influence from Yogacara. There have been questions regarding the translation of this sutra as it was not sponsored by the Imperial Chinese Court and as such the records regarding its translation in the early eighth century were not carefully preserved (see History); however, it has never been classified as apocrypha in any Chinese-language Tripitakas including the Taisho Tripitaka where it is placed in the Esoteric Sutra category (密教部). The sutra was translated into Tibetan during the late eighth to early ninth century and a complete translation exists in Tibetan, Mongolian and the Manchu languages (see Translations). Current consensus is that the text is a compilation of Indic materials with extensive editing in China, rather than a translation of a single text from Sanskrit. A Sanskrit language palm leaf manuscript consisting of 226 leaves with 6 leaves missing which according to the introduction "contains the Śūraṅgama Sūtra" was discovered in a temple in China; it has yet to be verified.