Abstract:The paper first analyzes what makes reduction in simultaneous interpreting(SI) necessary, then explores, through the lens of prototype theory of cognitive linguistics, where reduction in SI is theoretically based, and how reduction strategies such as information selection and processing strategies work in SI at conferences against the fast-paced, information-intensive and unclear and illogical source speech.It proposes the notions"Family of Target Speech" and "Target Speech Continuum" so as to inform SI practice, pedagogy and quality evaluation.