“A ye bushi（也不是）, B ye bushi（也不是）” is a widely used sentence pattern in modern spoken Chinese. This sentence pattern has a simple structure and a fixed construction meaning. The former part and the latter part of the sentence pattern represent symmetry and cohesion. This paper intends to give this sentence pattern an intensive analysis, including structure, meaning and function. A description will also be given of the emergence and development process from the diachronic aspect, trying to use Cognitive Linguistic theories to explain the mechanism of the sentence pattern’s creation and evolution.