The Kula Ring, or kula exchange, refers to the gift exchange of shell valuables in the islands of the Massim, in Milne Bay Province, Papua New Guinea. Partners exchange one of two different kinds of valuables, and receive the other kind of valuable in return. The two types of valuables are mwali, an armband fashioned from Conus shell, and bagi (or soulava), a necklace of discs made from red Spondylus shells.

Partnerships in kula span islands and link different communities. For instance, a Kiriwina (Trobriand Islands) kula participant receives bagi from his partner in the south, on Dobu Island, and gives this bagi to another partner on Muyuw (Woodlark Island), to the east. Each valuable received must be reciprocated later by a valuable of the other type of similar size and prestige. In this way, kula valuables move in a ring from island to island, bagi moving in the opposite direction as mwali.

Kula valuables are ranked according to size and the history of their movement from partner to partner around the ring. The most prestigious valuables are named, unique objects. They are supposed to move according to a 'road' (keda) among a set of prestigious, experienced kula partners; ideally, a valuable should travel its road, from hand to hand, around the ring, and return back–perhaps years later–to the hand of the same person. This particular feature of kula exchange was important for the anthropologist Bronislaw Malinowski, who wrote the seminal account of kula in his book The Argonauts of the Western Pacific (1932 [1922]). For Malinowski, kula exchange was distinct from trade or barter. Unlike these forms of exchange, kula was ceremonial, formal exchange among an elite group. While it was itself not economic in nature, it facilitated peaceable relations among distinct groups and made it possible for them to trade, as well as gave the participants a venue for competing for their own prestige. This view of kula as a ritual of exchange governed by strict rules in turn influenced Marcel Mauss in his development of a theory of the gift (2000 [1925]). For Mauss, kula was an example of a system of total services, because the rules bound partners together and regulated the movement of valuables.

Malinowski, Bronislaw. 1932 [1922]. Argonauts of The Western Pacific: An Account of Native Enterprise and Adventure in the Archipelagoes of Melanesian New Guinea. London: George Routledge and Sons, Ltd.

Mauss, Marcel. 2000 [1925]. The Gift: The Form and Reason for Exchange in Archaic Societies. Translated by W. D. Halls. New York: W. W. Norton & Company.