Adaptation is a method commonly used in interpreting and translation, however, theorists have not reached an agreement on its strength and limitations. On one hand, adaptation is considered a type of interpreting and translation, a creative process, an essential act to express the meaning of discourse and maintain the balance of inter-language communication activities. On the other hand, some authors claim that adaptation is not interpreting and has the same meaning with paraphrasing. So how should adaptation be figured out? Which criteria affirm the importance and properness of adaptation? This article tries to answer these questions.