At the climax of the May 4th movement,a cultural controversy about east and west occurred between Chen Du-xiu and Du Ya-quan.The review about this controversy is simplified in the past;on the other hand,the revaluation based on the conservatism standpoint since 1990s is also suspectable.So we should to liquidate this controversy.The bifurcations of Chen and Du rest with: The first,Chen Du-xiu committed himself to animadverting despotism and vocalizing thought freedom,Du Ya-quan was accustomed to the unification of thought and cultural system;The second,Chen Du-xiu committed himself to animadverting connatural culture and introduction of west culture,but Du Ya-quan opposite it.The third,Du Ya-quan took the connatural culture as the basis of our country,but Chen Du-xiu regarded the connatural culture as a block of democracy.Maybe we can say that Chen Du-xiu is as important as Cai E when they made great efforts to protecting the Republic regime.Any revaluation must take this historical fact as the base.