The present paper is an analytical description of a market settlement, Ouélessébougon, on a savannah hilly region in southern Mali. The data analyzed here were collected during the period of February-April of 1968 by the writer, then a member of the Kyoto University Scientific Expedition to the Sahara. Ouélessébougou contains a population of more or less 3000: they live in what are commonly called “compounds” in African ethnography, totalling 272 in the area. The area is located along the national road that links Bamako, the capital of the Mali Republic, with Bougouni, another conspicuous town in southern Mali. This road follows the earlier trade route along which salt from the Sahara was exchanged for kola nuts of the southern forestland. The Formation of the market in Ouélessébougou in the late nineteenth century was an obvious result of functioning of this trade route. This market now plays an important role in the market ring embracing other seven markets in the neighboring areas. The very existence of the market has been the primary effective cause of the differentiation processes within the settlement that has eventually outgrown an earlier homogeneous Bambara village: incorporation of a variety of tribes and occupational differences have occurred. At present three social groups can be demarcated: the traditional Bambara farmers, chiefly the descendants of the pioneers of Ouélessébougou; the Islamized merchants: and finally newcomers. Owing to the administrative, educational, and other important functions imposed on the settlement, it is now rising above the traditionol village level organization. The writer concludes that many charcteristics Ouélessébougou are indicative of a type case of the emerging town level market settlements in the West Sudan.