An important platform for Chinese enterprises to “go global” under the initiative of “the Belt and Road Initiative” is overseas zones, which help enhance the international competitiveness of Chinese enterprises. In recent years, a large number of researchers focus on the development of overseas zones; however, they seem to have failed to keep pace with the development of zones or to identify the major challenges faced by zones outside China. This paper adopts the Michael Porter Diamond Model, which intends to compare and analyze the advantages and disadvantages of the development of Cambodia-Japan Phnom Penh Special Economic Zone (PPSEZ) and Cambodia Sihanoukvilleville Special Economic Zone (SSEZ) and discusses the advantages and disadvantages of the development of overseas zones.In the 1990s, Michael E. Porter at Harvard University put forward a Diamond-shaped Framework, a new method to understand the competitive position of a country or the world. He developed the traditional comparative advantage theory and progressed from comparative advantage to competitive advantage, which had a great influence on theory and practice. Porter holds that the industry must have the following four basic elements to gain a competitive advantage in the world: production factors, demand conditions, related and supporting industries and enterprise strategies, as well as the competitive structure and peer competition. In addition, government actions and opportunities also have a great impact on the competitive advantage of the industry. The above elements could reinforce each other, jointly composing a “Diamond Model” that affects the competitiveness of the industry. This model is mostly applied in analyzing the advantages of enterprise or industry development in China. And there are bound to be new discoveries when the model is applied in analyzing the advantages and disadvantages of the development of Chinese zones overseas.