Abstract: The entity as a whole composed by units of parallelism can be labeled as "chunk of parallelism",which is the extraordinarily striking segment of parole.The "chunk of parallelism" in loose sentence is the part,to which the speaker or writer attaches most potent expression,prominence of connotation and the strongest emotion,and also the part impresses the listeners and readers most.In the thesis,the author elaborates the type of contextual cohesion,the function of sentencemaking and textual arrangement,the location in the text,consecutive use,effects of conveying emotion and meaning and so on.The idea and perspective of exploring parallelism as a whole in text brings about a more comprehensive and creative understanding of parallelism to us.