In Taiwan’s law, buildings and land are both independent real estate objects, which is not like German law. In German law, buildings are the component of land. We can also call Taiwan’s legal structures “dualism”. Under dualism, the ownership of land and buildings may belong to different person and it leads that disputes between the ownership of buildings and land because of the claims for removal and restitution from land’s owner. It is a vital issue that how to make sure the ownership of buildings acquire the legally right so that it could prevent social economy from injury. Taiwan’s legal structure includes a series of regulations, which are aim to solve the issues we mentioned above. These regulations could be summarized into one concept “Principle of Integration”, disposition of integration and ownership of integration included. Two sub-principles have their own effect respectively. Disposition of integration plays a role in the process of disposition, enforcing that buildings and land or right, which is the basis for the building’s owner to use the land shall not transfer separately. This principle could achieve the goal that transferee of the building has the legally right to take the possession of the land. The third chapter of this thesis introduce and deal with the regulations related to Disposition of integration, considering that this principle shall extend scope of application. Furthermore, this thesis also believe that Article 426-1 of the Taiwanese Civil Code and servitude of real property are likewise the instances of disposition of integration. Ownership of integration plays a role in the result of disposition. With the right of first refusal in building site lease contract and regulations, transferee of the building could acquire ownership of land or right, which is the basis for the building’s owner to use the land. Article 426-2 of the Taiwanese Civil Code and Article 104 of the Land Act are the instances of the right of first refusal in building site lease contract. The regulating purpose of Article 425-1, Article 838-1, and Article876 of the Taiwanese Civil Code is exactly ownership of integration. Discussing the right of first refusal in building site lease contract, this thesis believes that this right of first refusal shall extend scope of application but not blindly. By way of illustration, this thesis consider that borrower of the land loan contract cannot claim this right of first refusal. Dealing with the regulations related to the ownership of integration, first of all, the thesis induces the basis for application. Afterwards this paper introduces the element “owned by the same person”, analyzing a wild variety of controversial cases which were decided by the court and proposing whether they fulfill the element or not. Last but not least, this thesis claim that legislators shall amend Civil Code, merging 3 regulations into 1.