Abstract: With the arrival of the information age, enterpris es are increasingly using computer-mediated communication ways in their routine business and the traditional ways of communication, mostly face to face communi cation, are to some extent overlooked. This paper studies the effectivity of com puter-mediated communication and traditional face-to face communication based on knowledge, with the purpose of gaining an insight into the knowledge nature o f modern communication. The study shows that the effectivity of the two communic ation ways varies with the task types. Enterprises must take both communication effect and communication effectivity into account, on which to base their choice of appropriate communication way. Thus they could generate the core competing c ompetence for the enterprises.