Although previous researchers have pointed out that articles with the signature"Duying"are also related to Lu Xun,there has always been a lack of conclusive evidence.According to the letter from"Duying"to Qian Xuantong included in Vol-ume 7 of the"Series of Letters from Chinese Modern and Contemporary Celebrities"compiled by Beijing Luxun Museum(Volume of Zhou Zuoren),and compared with the letter from Qian Xuantong to Lu Xun included in the"Collected Works of Qian Xuantong",new evidence is provided that"Duying"is the common pen name of the two brothers.According to the ex-isting 20 letters from Lu Xun to Zhou Zuoren,it is pointed out that the cooperation between Lu Xun and Zhou Zuoren in trans-lation presents a more complex landscape than the cooperation between Lin Shu and Wei Yi.Therefore,it is proposed that re-searchers should not only pay attention to the"division"of the Zhou brothers,but also attach importance to their"unity".