When the industries agglomerate in an area, an industrial area is formed. In this report, I am intending to analyse the elements cause the industries to agglomerate in an area. These elements can be devided into two factors (1) geographical factors of industrial position and (2) the industrial factors for localization. The geographical factors are the naturall and social conditions of the geographical position to make the growth of industry possible, and the industrial factors mean the condition on which an industry can develop at a pl ace. (1) Geographical factors: Accumulation and combination. Accumulation; the case that the factors of a place, which can develop an industry, are fit for other industries at the same time. Combination; Combination of the industrial places or industrialization of the environs of the industrial area, that is, formation of the larger industrial area by combination of some industrial areas. The accumulation factors are deviled into such elements as materials, labor, power and fuel, and market factors. (2) Industrial factors: Duplication and continuation. Duplication The industries have the common industrial factors of the same hind, which conform to geographical farctors of a place. The duplication factors are devided into several elements of materials, labor, power and fuel, market, and nature. Combination: Three cases are exemplified; the finished goods of an industry are the materials of the other industry. The by-prod cots of an industry, the finished goods of an industry take the auxiliary part for the other industry.