Changes in levels of cortisol, glucose, Na+, Cl-, K+ ions, muscle water content, the size and number of gill chloride cells as well as mortality percentage of Convict Cichlid (Cichlasoma nigrofasciatum) with mean weight of 3.70±0.93 g were investigated under various salinities (fresh water, 10 and 20 gl-1) and temperatures (20, 25 and 35oC) for 60 days. Sampling was done at the beginning of the test, and the days of 30 and 60 after the test. Cortisol, glucose, Na+, Cl-, K+ ions, the size and number of gill chloride cells were increased after 30 days of the test and the maximum levels were obtained in 20 gl-1 at 20oC on day 30 of the test. Muscle water content were decrease after 30 days of the test and the minimum level was obtained in 20 gl-1 at 20oC on 30 days of the test. Mortality percentage was increased after 30 days of the test and reached the maximum level in 20 gl-1 at 20oC on 30 days of the test. All of the fish were died until the end of the experiment. Based on obtained results, it seems that the salinity more than 10 g -l and temperature lower than 25oC is not suitable for rearing of Convict Cichlid.