Unlike proceedings in judicial authorities, the way of violating the decision in Arbitrations is only possible through annulment and the second point is that there is a fundamental difference between Revision and annulment, as well as between these two institutions with revision of opinion. It is not possible to appeal in arbitrations. Annulment of the award issued in ICSID requires compliance with the rules and principles specified in the convention. Documented in paragraph d (1) of article 52 of the convention, one of the reasons for annulment of the decision in the ICSID is the appeal of the annulment petitioner to hat there has been a serious departure from a fundamental rule of procedure. The mentioned article refers to the generalities of this matter and has left the discovery and inference of its examples and differences to custom and practice. The current article, which is done in a descriptive-analytical way, in order to answer this question, what are the examples of violation of the basic rules of proceedings. For this purpose, we have started to study the procedure of ICSID. The result is that, firstly, the scope of the examples is not statistical and limited, and secondly, the examples must have serious and fundamental characteristics, and thirdly, the examples cited in the ICSID procedure include the violation of the right to be heard, the issue of evidence and the burden of proving evidence, non-observance of independence and impartiality. The jury and the lack of enthusiasm among the members of the jury