The purpose of this study is to analyze the fundamental factors of site location in the plastic model kit industry in Shizuoka region,Japan.Shizuoka holds a 80% share of the production value in plastic model kits industry.And Shizuoka region has the greatest number of firms in Japan.Eight firms located in Shizuoka are listed on the data by an industry organization.These firms can be classified into two types by established year; older firms and newer firms.Older firms are established before 1970’s and newer firms are established after 2000’s.Older firms changed the field of business activities from woody model kits to plastic model kits expect one firm changed from textile industry.All of newer firms are spin-off from these older firms and have been producing plastic model kits since they were established.The firm size of newer firms is small.Some of old firms are nearly large firms from the standpoint of the capital size and the number of employees.Three firms are picked up in this study from the standpoint of revealing transaction relationships between firms and subcontractors in Shizuoka region: (1) Firm E,is large firm and have many manufacturing process by their own.(2) Firm G and (3) Firm H,are small firms and only have specific process and they build relationship with several subcontractors.Some of subcontractors with Firm G are located outside of Shizuoka region,but those with Firm H are located in Shizuoka.This difference is expected to affect the structural difference in division of labor between Firm G and H.Analysis about the characteristics of product feature and transactions reveals the following facts about the industry.Firm E did not have the technology manufacture plastic models because it is originated from the textile enterprise in Tokyo.It acquires current plastic model manufacturing technology buying out metal mold manufacturing company and model manufacturing company in the process of their business expansion.After the plant was relocated,Firm E increased the investment on the plastic model manufacturing technology.Its objectives are self-manufacturing and improving the productivity by introducing leading-edge technologies such as multicolor injection machines and 3D modeling machines.Their major target is domestic market,and especially the share of the tie-up product with TV animation is large.The period TV animation broadcasted is usually from three months to one year.Firms need to develop and manufacture the plastic model during this period.This short period of time spend on developing and manufacturing is the one of the determinant factor that Firm E is located and concentrates its process of works in Shizuoka,which is close to the market and the technology accumulated.The firm manager of both G and H are from the manager in the engineering department of leading enterprises in plastic model manufacturing.These two firms have specialized process and technologies and develop products with using such technologies after their independence.Their core products are the scale model from particular model or type of vehicle and so the width of their product line is not broad.The sales from old product lines are spent on the new product development.A number of production lots is not high,and firms require some time for collection of sales proceeds.Firm G and H spend more time on the development than Firm E does.Firm G has their subcontractors from other prefectures of areas,and the plastic model lover or old coworkers introduce these subcontractors.On the other hand,Firm H takes over subcontractors from previous company,which the manager of Firm H once belonged to.Although Firm G and Firm H have different type of production footholds,the subcontractors are from networks formed during the work experience in Shizuoka.These factors indicate that being located in Shizuoka leads to the competitive advantage of these firms regardless of firms’ origin,size or core products.