In modern society, we are very frequently faced with the various kinds of force majeures including not only acts of Gods such as earthquakes, floods, typhoons etc. but also the man-made contingencies, for example, war, revolution, riot, civil commotion, strike, embargo, government restrictions etc. These all kinds of force majeures give our society, occasionally, a lot of risks and huge loss to insurmountable extent, because of its distinctions of unforeseeability, uncontrollability for humankind. By the way, force majeure events also are very important for the various international commercial contracts including international contract of sale of goods, construction and engineering, plant supply etc. Especially belong to the long term agreement, because in case of force majeures after formation of contract the affected parties may be excused(exempted) from his liability to perform. All the nations in the world have the almost same provisons in their civil code or commercial code which articulates the excuse by applying the force majeure doctrine has a long history. It originates from the exempting the principle of clausula rebus sic santabus in ancient Roman law as a counter-principle of the so-called pacta sunt servanda that is a basis of principle of sanctity of contract or absolute liability of contract. By recognizing force majeure doctrine, most international business agreement has force majeure clauses. However, there are many problems in invoking force majeure excuse. It is never simple and easy to use it in spite of force majeure clauses in the contract. Frist reason is “definition problem” of force majeure. In fact, the word “Force Majeure” is French term which comes from the Code Napoléon even though it is widely used in other nations influenced much by French law. But so many countries use different terminologies, For example, the word “frustration” in used in England, “Wegfall der Geschäftsgrundlage” in Germany, “commercial impracticability”and occasionally “frustration of purpose” in USA. By the way, the definitions are quite different each other. Moreover, the legal requirements and effects also are not the same, which arouse much confusion and difficulty in understanding and applicating these force majeure-type events. So international organizations have arranged some international convention or uniform rules including UN’s CISG, Unidroit’s PICC, ICC’s Force Majeure Clause and Hardship Clause etc. Nevertheless, CISG and PICC also have shown its limit in unifying the definition, requirements and effects of force majeure-type event. Recognizing these current issues relevant to the force majeure-typed circumstances in the legal field of contractual liability, the aims of this thesis are firstly to streamline and compare the doctrines and domestic legal systems of force majeure-type events in main countries, and also the international norms such as CISG and PICC as well as ICC Force Majeure Clause and Hardship Clause. The research also examine the legal and practical knowledge which is necessary to draft the effective and reasonable force majeure clause to give help to business circles when they make an agreement on sale of goods, overseas construction works, and other international long-term projects. In result of this literatural thesis, the author can finds the following points which are recognized as important.1) Even though the principle of sanctity or pacta sunt servanda is a basic principle in the contract low from the Roman Empire, it is not absolute and there are legal exceptions or limit to its strict application when performance is prevented or delayed by the unforeseen events such as force majeure which if beyond the parties’s control. Accordingly there has been a consensus major systems to grant the non-performing party immunity from liability for non-performance. This legal philosophy of exceptional exemption is rooted on the clausula, rebus sic stantibus principle which developed in the late medieval period in accordance with economic, legal and business realities underling a contractual agreement. However, major countries had developed its own legal doctrines for the purpose of settling cases of supervening events using different terminologies each other, and it arouse a “definition problem” in international business fields. Namely, there are different legal terminologies such as French force majeure and imprévision, German Wegfall der Geschäftsgrundlage, English frustration, and American impracticability etc. All of these are the legal concepts to settle the case of the nonperformance of contract due to the supervening events out of control. Nevertheless, the requirements and legal effects is quite different. Namely, some systems accept only a narrow range of excuses, and others are more generous for pleading the supervening events for exemption of the non-performing party.2) There are same complication even in case of international convention, principles or guides, even though those have much contribute to unify international norms in relation to the exemption of liability of the parties in case of the impediments that are out of control or excessively burdensome. However, comparative study of this thesis shows several important limitations. First, there are also terminological difference among the CISG, PICC, and ICC’s force majeure clause/hardship clause, and their terminologies used to treat excuse liability of nonperforming party due to the supervening events is different, especially between CISG and PICC. And also the scopes of CISG and PICC are different. For example hardship is not claused in CISG, differently from PICC which clauses force majeure as well as hardship.3) Concerning practical application of doctrine of force majeure, there are many points to be recognized as important. But, the author would like to make reference only the following comparatively more important points omitting others. First, force majeure clauses that excuse a nonperforming party from liability are common in almost international business contract. But it is not given attention during the negotiation of contract. So, parties often insert “boilerplate” force majeure clause into their contract, but it is not desirable very much because it might lead to problems if a force majeure events materialize later. Therefore, “tailored” force majeure clauses are absolutely important especially because international arbitral tribunals are as a rule reluctant to interfere with a contract without a specific contractual basis. second, applicable law may play an important role in interpreting the force majeure clause in the contract or the force majeure doctrine. Therefore it is important for contract drafters to understand whether, and if so how, the potential applicable laws provide for and define the doctrine of force majeure. Third, When well drafted, force majeure clauses maximize the protection of contracting parties and minimize the likelihood of unintended consequences. So, the words in the contract should be expressed exactly in accordance with the applicable law. Fourth, because there are many point to check when parties negotiate the contract which force majeure clause is included, it is desirable for drafters to use a checklist which is well designed.