"Style" is a key concept in modern art history. Its rich implications and inherent contradictions, however, make its connotation ambiguous. By way of examining the birth, development and evolvement of this concept in art criticism, this paper tries to expose the meaning of style which shifts from "maniera" to "stile," and describe its constant transformation in the evolving history of style. The analysis in the paper shows that it is the rich connotation and evolution of style that makes the history of style a dominant paradigm in the construction of traditional Western art history, while the dilemma that the history of style is facing today may provide a point of departure in our rethinking of the construction of art history.