Since 1980, a wave of new regulatory reform policies washed over the world, tightly controlled industries shrugged off their chains, and public institutions were privatized. The wellspring of regulatory reform is the global trend towards liberalization and privatization. Even so, the scope of government regulation is still wide, but the processes of this type of control changed and the administrative acts diversified. Among these administrative acts, the administrative contract is much more special than others. First of all, unlike other legal concepts that were important from German or Japan, it is a unique system in French administrative law. Secondly, the special mission of administrative contracts merits attention. Although we called it an administrative "contracts", some government privileges are attached to realize the administrative object. After the enactment of Administrative Procedures Law in 1998, the administrative contract has been recognized as a formal act in Taiwan, and it is important to know how to use it. Therefore, the aim of this thesis is to find the solutions given to problems arising in our administrative law through understanding how administrative contracts work in France. To understand the notion clearly and correctly, we shall find the source of administrative contracts and then study the definition. The two basic criteria of the former are that the contract relates to a public service and the contract reserves exceptional powers to the administration (the clauses exorbitantes du droit commun). In Taiwan, the definition of administrative contracts is similar, but the criteria are quite different. To learn French experience in this regard for the purpose of the improvement of our system is the topic issue in the chapter second. However, the definition is just a basis to develop my issue in this thesis. This thesis focuses on the effect and execution of administrative contracts. At the third and the fourth chapter, I will devote more space to discuss how an administrative contract is made and the value of the intentions of the parties. Because of the France has always regarded an administrative contract as essentially an arrangement between unequal parties, public authorities have powers to redefine the character of the service to performed or the work to be done in order to meet the changing needs of the public interest. How about the administrative contracts work in Taiwan? Do we admit exceptional powers to the administration? What are the differences between the regulations in France and Taiwan? After an initial research, I find that the underlying foundations of administrative contracts in two countries are quite different, so the systems appear differently. However, identifying foreign precedents on similar problems and their possible solutions will certainly provide useful insights for local consumption. In addition, of course, I deal with a review of the concept of administrative contract in the Supreme Court Justices' decisions in the Judicial Yuan to figure out the main change of our jurisprudence. Then try to organize the judgments in the Administrative Court from 1999 when the Administrative Procedure Law and Administrative Litigation Law were significant legislated. Based on the research in this study, I examine the main categories of existing contract -B.O.T.- with the comparison between Taiwan and France. So what could we do more and learn from the experience in France is the topic issues in the fifth chapter. The final chapter is the general observations. As we know, our law on administration is far less developed than that in France. Much of it remains in the realm of practice rather than law. Nevertheless, there are increasing pressures for our law in this field to develop：changes are being made by significant legislations of the Administrative Procedure Law and Administrative Litigation Law. Our scholars as well as judges work very hard to build a modern system of administrative law .As a result, the French systematization in this area will provide a much-needed guide when we facing the same problems in the future, which will be encountered as our law develops.