The paper mainly makes a diachronic study on the use of 'dabuliao(大不了)'.At first, the paper investigates the eXpressional function of 'dabuliao(大不了)' in Contemporary Chinese.Then,it carries out a diachronic study.The research shows that there are three kinds of 'dabuliao(大不了)' in Contemporary Chinese,a phrase,an adjective and an adverb,which were not originated from the adverbial-head structure 'dabuliao(大不了)' in the Five Dynasties,but formed under the influence of the semantic change of its components and the analogy of 'V buliao(不了)' structure ...