在傳統的零售據點選擇策略中，常會考慮到同行競爭的問題，故大多儘量會避免商圈的重疊，以確保商店單店的基本市場佔有率。但在大都市的市中心，常會發現同類型商店多家相鄰設立的情況，本研究稱此現象為「聚集」。在眾多商店聚集的情況下，各商店的商卷必然彼此相互重疊，此顯示出傳統的商圈理論並未能適用於中心商業區。因此，有必要探討商店聚集的現象，以及商店聚集所產生的聚集效益，以說明商店聚集的原因。本研究以台南市中心商業區為例，對中心商業區內之主要商店街進行業種掃街調查。首先，利用業種調查之結果，分析主要商店街之業種結構與特性。接著，針對中心商業區主要業種（家數比率佔前幾名者），透過商店分佈為隨機率分配的假設，來探求各主要業種是否在中心商業區有聚集之現象。其次，本研究將探討地價與業種類型之關係，以分析地價高低對業種分布之影響。最後，以婚紗、書局、電腦資訊等三個業種為例，利用判別分析，進一步探求經營績效與聚集強度之間的關係。

Traditionally, the strategy of selecting the location of a retail store is based on the distance with a competitor to avoid the overlapping of business and to assure the basic market share of the store in the area. But, in reverse, it's easy to be found that same type of stores are neighboring each other in the downtown area of a big city. This research names this kind of commercial phenomenon as "clustering" . Due there are too much stores to get together in downtown-even on the same street, the same types of stores must overlap with each other undoubtedly. It shows that the traditional theory of selecting the stores location is completely improper to the real situation happened in downtown area. Therefore, it is valuable to probe into all these same type of stores in gathering. Why do these same type of stores get together closely, and how can they still get the profits. This study takes Tainan's downtown as an instance. We investigated along the main commercial streets to check the professions of the stores there. Then, by using the results after the investigation, we can analyze the occupational structure of the stores on the main streets and their characteristics. We select the most presented stores as research samples. Through the use of random probability on stores distribution, we can identify whether selected type of stores cluster or not. At Tainan's downtown, we take three kinds professions as samples-wedding garment stores, book stores, and computer stores. By using our analysis, we can find out the relationship between management efficiency and the intensity of same type of stores in gathering.