As we all know, sometimes the pracitces change so fast and the rules may have some problems. So we need to modify or amend the rules that has already existed. And when it comes to treaties, Vienna Convention on the Law of Treaties have already given us some regulations about the modification of treaties. When it comes to the U.N. Charter, according to article 108 of itself, two thirds agreements of state parties is necessary. And also, two thirds ratification is also important.That`s qualified majority. And what about other treaties? Actually all parties, or qualified majority for multilateral agreements is required to modify or amend multilateral treaties, and all parties necessary for bilteral treaties.