The prohibition modification or expansion of claim is accepted in consequence of maxim of concentration as one of the prevailing principles in procedural law. The prohibition modification or expansion of claim begins after the pleading stage of a lawsuit. By means of exceptions of the prohibition, this strict principle is lightened. The prohibition of modification or expansion of defendant’s defense and plaintiff’s claim can be removed with amendment or explicit consent of opposite party as exceptions of prohibition. In case of lack of explicit consent, the defendant and the plaintiff are able to make changes to their claims and defenses by using amendment procedure. By amendment procedure, the parties assert new claims and recover their procedural actions. Within this scope, an amended plaintiff’s case might contain new claims not previously asserted or an amended defendant’s defense might include new defenses not previously raised. The parties are able to make amendment only once during a jurisdiction. In this study, time limit of the procedure of amendment will be examined in the light of the decisions of court of Cassation and doctrine opinions. Within this scope, starting and ending time of amendment and specially applicability of amendment procedure upon the annulment decision of the court of Cassation or reversal decision of regional court of justice will be evaluated.