Chemical alarm cues (CACs) play an important role in fish predator-prey interactions. To explore the model and plasticity of chemical alarm communication of fish, and to test the niche hypothesis of the chemical alarm response in fish, adult Rhodeus ocellatus individuals were exposed to either predator treatment or no predator treatment for 8 months, using the common garden experiment. Subsequently, the behavioral responses of adult and juvenile R. ocellatus to different chemical cues within the environment (water control, juvenile and adult CACs of R. ocellatus, and the predatory cue of Channa argus) were measured under different predation contexts. The results showed that in the predator-free treatment group, chemical information had a significant effect on the changes in motionless time of adult R. ocellatus (P＜0.05) but had no significant effect on the changes in motionless time juvenile R. ocellatus (P＞0.05). There was a significant difference in the changes in motionless time in response to predatory cues between adult and juvenile R. ocellatus (P＜0.05). However, in the predator treatment group, the changes in motionless time for both the adult and juvenile R. ocellatus had a significant response to all risky cues, including the CACs of juvenile and adult R. ocellatus, and the predatory cue of C. argus (P＜0.05). There was no significant difference between adult and juvenile R. ocellatus in behavioral response to a given chemical cue (P＞0.05). These results confirm the hypothesis that chemical alarm communication in R. ocellatus is dependent on the environment and the chemical alarm response model of R. ocellatus, in predation contexts, supports the niche hypothesis of the chemical alarm response in fish.