To explore the changing rules of water quality indexes and the differences of aquaculture benefits in different aquaculture systems of Ctenopharyngodon idella, three aquaculture models were set up, namely Ctenopharyngodon idella cum Litopenaeus Vannamei mixed culture model (model 1), Ctenopharyngodon idella cum Trionyx Sinensis culture model (model 2), as well as Ctenopharyngodon idella monoculture model (model 3). The total ammonia nitrogen (TAN), nitrite nitrogen (NO-N), nitrate nitrogen (NO-N), pH, permanganate index CODMn, total nitrogen (TN), total phosphorus (TP), aquaculture yield and net profit in different aquaculture models were determined and analyzed. The results showed that in model 1 and 2, the concentrations of NO-N exhibited a decreasing trend with the increase of culture time, NO-N concentration increased first and then decreased, and at the later stage of aquaculture, the concentrations of NO-N and NO-N were significantly lower than that in model 3 (P<0.05). However, there were no significant regular changes in TAN concentrations in all three models, and no significant differences at the later culture stage among them. CODMn concentrations in the three models had no significant difference (P>0.05) , but they all showed a gradually increasing trend. The pH of model 1 was always greater than that of model 3, and was significantly greater than model 2 and 3 at the middle and late culture periods. The concentrations of TN and TP in three models all gradually increased with time, while they were lower in model 1 and 2 were than in model 3, and differences became significant in October 12 (P<0.05). In terms of aquaculture benefits, model 2 had the highest unit yield, higher total output value and net profit than the other two models, and followed by model 1. The results showed that the two polyculture models of Ctenopharyngodon idella were better than the monoculture model in terms of water quality factors and aquaculture benefits, and the Ctenopharyngodon idella cum Trionyx Sinensis culture model was the best.