Inlate-Qing and early Republican China,yulun was considered an important force for political and social change,which took on an ascending tendency in intellectuals’ speaking. The meaning ofyulun shifted significantly on ethical,epistemological and political levels. "Constructing Sound Opinions"became the group consciousness. However,facing a more realistic picture,the consensus of intellectuals shifted from"mother of public opinion"to "enemy of public opinion". Yulun almost became a negative word,subsequently replaced by "-ism ". The last part of the article makes an preliminary analysis on the dilemma and tendency of public opinion in modern China from the perspective of the inherent tension of description.