Abstract: Personal involvement is an interpersonal strategy for the communicative purpose of academic texts.Among all the expressions of personal involvement, the first person we is used far more frequently than any other types and has the most complicated semantics.Based on corpus data, this paper generalizes and describes the characteristics of we in hard science articles with regard to its frequency distributions, semantic references and discourse acts.Findings suggest that in recent years we has been increasingly used in hard science articles either to construct salient authorial identity or to interact with readers; in particular, it has four kinds of semantic references:i.e.writer, writer-reader, the whole discipline, and general people.We under each semantic category can perform multiple academic discourse acts by collocating with different verbs to form various co-selection patterns.This study offers a short-cut for novice academic writers to achieving higher accuracy and idiomaticity in language use.In this sense it may have potentially valuable implications for EAP teaching.