Lots of application systems are developed for applying business GIS in marketing or strategic planning of the company, recently. Almost of the systems require statistics for some areas(trade areas or sales areas) as the important information of decision support. As far as now, trade areas are defined for individual stores using know-how of the specialists, but there is no well-defined method for defining of trade areas of the specific business domains or trade areas of the customers. In this study, we have applied the spatial data mining methods to the point features in GIS, evaluated the results of each methods, and discussed the feasibility of defining of trade areas. From the results of this study, we have concluded that the defining of trade areas from point features, such as franchisees of credit card company or memberships of retail chain store, and that the DENCLUE(DENsity-based CLUstEring) method is the best suitable spatial data mining algorithm for this purpose.