[Objectives] To understand the species of Dactylogyrus that infect Gobio acutipinnatus in the Irtysh River in Xinjiang, China, this study collected 510 ind of G. acutipinnatus from the Haba River (a tributary of the Irtysh River) between July 2021 and August 2023. [Methods] Morphological methods and molecular biological techniques were employed to identify the Dactylogyrus species collected from the gills of G. acutipinnatus. The morphological characteristics of this species were illustrated, measured, and compared with previously reported morphological data of Dactylogyrus parasitizing G. acutipinnatus from both domestic and international sources. The 18S-ITS1-5.8S rDNA sequences were amplified, and sequence alignment was performed by BLAST in the NCBI database. Based on the 18S-ITS1-5.8S rDNA sequences, the base composition was calculated by MEGA 7.0.20, and the Kimura-2-parameter (K2P) model was adopted to calculate the genetic distances between species. PhyloSuite was used for multiple sequence alignment, and the best-fit model was selected through Akaike Information Criterion (AIC) testing with ModelFinder. Based on the selected model, phylogenetic trees were constructed by both Bayesian inference (BI) and maximum likelihood (ML) methods to validate the phylogenetic relationships of parasitic Dactylogyrus. [Results] The collected Dactylogyrus species had a straight line-shaped dorsal bar, with two ends protruding backward and slightly wider in the middle. The ventral bar is straight line-shaped, with narrow ends, extending to the front and slightly wider in the middle. The copulatory tube is a thick bend, with the thickest starting part and a thin tail. The accessory piece is thin tubular, starting from the top of the copulatory tube and bifurcating at the tail end, forming long and short sheet branches at both sides of the copulatory tube (Figs. 1, 2). Consistent with the D. gobii parasitizing G. acutipinnatus of Kazakhstan in the copulatory organ and opisthaptor, the D.gobii parasitizing gills of the G. acutipinnatus inhabiting the Irtysh River, China was identified as D. gobii according to morphological characteristics (Table 3). The characteristic structure of this parasite differed from those of other Dactylogyrus species parasitizing Gobio. The opisthaptor shape of D. gobii is most similar to that of D. cryptomeres, varying only in the ratio of inner root and outer root for anchor, which was 4:3 for D. gobii and 2:1 for D. cryptomeres. The copulatory organs of both species of Dactylogyrus are curved tubular structures. In D. gobii, the accessory piece is in the form of a thin tube, starting from the tip of the copulatory organ and bifurcating into two branches, one long and one short, in the middle and rear part of the copulatory tube. For D. cryptomeres, the copulatory tube was relatively thick, with an enlarged top, and the accessory piece is in the shape of a flake-like mass, with the terminal end forming a sickle shape. D. gobii, D. cristatus, D. finitimus, and D. squameus possessed the D. extensus type of anchor, while only the anchor of D. gobiocypris was of the D. wunderi type. In addition, there are differences in the copulatory organ between D. gobii and D. gobiocypris. The accessory piece of the latter consists of two parts:one is horseshoe-shaped and the other is semi-saccular (Table 3). The18S-ITS1-5.8SrDNA sequence of D. gobii showed the highest similarity of 94.04% to that of D. cryptomeres. The genetic distances based on the 18S-ITS1-5.8S rDNA sequence between D. gobii and nine other species of Dactylogyrus varied within the range of 0.039﹣0.268, and D. gobii had the closest genetic distance (0.039) to the D. cryptomeres from G. gobio (Table 2). The phylogenetic trees indicated that the D. gobii determined in this study clustered into one clade with D. cryptomeres, D. finitimus, D. squamous, and D. gobiocypris parasitizing Gobioninae (Fig. 3). [Conclusion] The results showed that the D.gobii was a new record species of Dactylogyrus in China.