Abstract: Science communication alienation refers to the phenomenon of spreading pseudo-science and anti-science content in the name of science communication. According to the Marxist theory of labor alienation， science communication alienation can be divided into the alienation of science communication products， the alienation of science communication activity itself， the alienation of scientists image， and the relationship alienation among scientists， the media and the audience. Generated by the impact of social constructivism of scientific knowledge， science communication alienation views scientific knowledge as the social reality constructed from the media and the media as a chief constructor of scientific knowledge. Based on McLuhans media theory， it is the media form itself that may result in science communication alienation. An analysis of such theories helps to curb science communication alienation so as to ensure the accuracy and validity of science communication.

Key words: science communication, alienation, social constructivism, media