The purpose of this paper is to examine the major elements of Arbitration Clause in international investment contracts and to help the investor, especially foreign investors, considering these elements when they draft the contracts. First of all, to describe the extent of the arbitrable issues broadly is very important by using the phrase such as "disputes in connection with". Furthermore in order to be enforceable, the issues must be a subject-matter to be submitted to arbitration in accordance with the laws of the place of arbitration and the law application to the merits of the disputes (N.Y. Convention, Art. II). Second, the appointment of the arbitrators usually shall be based on the principle of freedom of contract. If the parties do not agree on the appointment, it is decided in accordance with the arbitration rules of the institution by the tribunal. Third, the procedural rules of the arbitration are the arbitration rules of the arbitration institution in case of institution arbitration, unless otherwise agreed. Forth, what is the most importance element of Arbitration Clause is the place of arbitration. In this case, also the principle of freedom of contract has priority. Unless otherwise agreed, Washington is the place of arbitration in case of ICSID Arbitration, but in case of ICC Arbitration, neutral third country may be the place of arbitration. However in case of ad hoc arbitration, both parties should indicate the place. If not, the whole arbitration may be paralysed by an uncooperative party. Besides the major elements, I examined the relation between the arbitration clause and award enforcement in terms of sovereign immunity. The enforcement of awards in the field of state contracts many encounter the problem of the sovereign immunity, which means that the State itself or the State enterprise is the contract partner. To avoid the this problems, it is advisable for the parties insert the clause such as ICSID Model Clause XIX.