While international patent law harmonization has been an issue in progress since the conclusion of the Paris Convention in 1883, it is facing new challenges due to the increasing dependence on patents in the knowledge-based economy and the growing sensitivity to the patent system's social and economic role in society. Inherently, the patent systems should be country-specific, given the industry-specific character of patent law. However, as the problem of fragmented patent laws caused by globalization became serious, the arguments for harmonizing patents laws obtained dominant support in the international community. This paper addresses the necessities for harmonization among countries by the economic model of game theory and highlights the relationship between the degree of economic openness and the harmonization of patent laws. This paper shows that as the world becomes globalized, one country should consider the other country's patent policy in deciding its patent policy and the government has an incentive to harmonize their patent policy with other country's policies.