Abstract: There have been increasingly more instances in recent years where states withdraw from a treaty unilaterally and in an arbitrary manner. This could impact to a large extent on the stability of international legal order,and harm the cooperation and efforts of international community on various significant global issues. Due to its defects in several aspects,current international legal regime concerning treaty withdrawal is incapable of reasonably and effectively restricting unilateral withdrawal actions. Moreover,implementing international responsibility resulting from unilateral treaty withdrawal is of immense difficulty. There is also a lack of clarity as to the rules regarding withdrawal from a treaty which has been signed but not come into effect. Unilateral treaty withdrawal must comply with not only the relevant treaty provisions,but also abide by fundamental principles of international law,including the principle of pacta sunt servanda,good faith,international cooperation,etc. For the purpose of improving the international regulation on unilateral treaty withdrawal,it is essential to define the foundation and limits of treaty withdrawal rights,strengthen the requirements and clarify the responsibilities for unilateral withdrawal,and promote the international cooperation on dealing with illegitimate unilateral treaty withdrawal actions.