Abstract: Diplozoon paradoxum (Nordmann, 1832) belongs to Platyhelminthes, Monogenea, Diplozoinae, Diplozoon. In this study, we reported this organism collected from the gills of Abramis brama orientalis (Berg, 1949) in the Ergis River (within China) from April 2009 to May 2013. Most of the morphological features of this newly found insect were the same as the original description of Diplozoon paradoxum (Nordmann, 1832), except for a few minor differences in the measurements. The genus, Diplozoon Nordmann, was reported for the first time in China. Here we described the morphological characteristics of this insect and showed the images. We analyzed its ITS2 rDNA sequence and compared the results with the parasite from the same subfamily in the GeneBank. The similarity between the newly found Chinese Diplozoon paradoxum and the European Diplozoon paradoxum was 99.5%. The distribution of Diplozoon paradoxum was also discussed in this paper.