The Amur sleeper Perccottus glenii Dybowski, 1877 is one of 9 foreign specie in the basins of Western Siberia. This specie didn’t make self-sustained populations after introduction, but they started self-expansion. The authors represent the data on the spread of this specie in the Ob within the South-Taiga zone of Western Siberia. The Amur Sleeper was observed in 50 % of the investigated basins, in 22 % floodplain lakes and the only taiga lake (12 % of the investigated lakes). The Amur sleeper is included into the structure of dominating fish. The authors explored the basins of the Chulym River and observed there fish aged 6+. The Philimonovsky pond is rich with the female-fish aged 3 y. o. (78 % of samples), and the Moiiseevsky pond is rich with female-fish aged 4 y. o. and 5 y.o (66 % of samples). The researchers observed the fish with length 46.5-128.3 mm and mass 3.1-88.6 g in the Philimonovsky pond whereas in the Moiseevsky pond the fish was 102.7-150.9 mm length and 29.6-102.8 g mass. The sexual dimophism appeared in the fish according to 13 out of 37 analysed plasticity parameters: the male-fish of the Amur Sleeper had thicker head, head depth through the back of the head and eye centre was higher, interorbital distance, the longest and the shortest body, basal length of dorsal fins and anal fins. The authors observed bigger pectroanal distance and longer abdominal fins in the female-fish. The differences in meristic parameters of female-fish and male-fish of the Amur Sleeper didn’t appear.