Lactoferrin (LF) is known as a functional glycoprotein originated from mammalian fluid. An eight weeks feeding trial was carried out to investigate effects of dietary bovine LF on growth, hematological, biochemical indices of blood, some non-specific immune factors, iron concentration in liver and muscle and intestine histology and microbial flora, heat stress and recovery rate to air exposure stress in African Cichlid Sciaenochromisfryei . Four different concentrations of LF (0, 200, 400 and 800 mg LF/kg diet) were supplemented in test diets and fed to the young fish (mean initial body weight: 5±0.1 g). There were three replicates for each treatment. At the end of the experiment, no significant differences were observed among all of the growth parameters among groups (P 0.05). Fish fed on 400 and 800 mg LF/kg diet showed significantly different contents of hemoglobin in comparison the other groups (P 0.05). Other hematological assays did not show significant differences (P 0.05). Total protein, albumin and globulin in plasma were not changed significantly (P 0.05). The lowest level of Alanine transaminase was in 400 mgLF which was significantly lower than the control fish (P 0.05). No other significant differences were observed in plasma biochemical indices. Serum iron decreased significantly in 400 mgLF diet in comparison to the control group (P 0.05). Total iron binding capacityresults showed that there were no significant differences among its levels in different treatments (P 0.05). Complement activity did not show any significant differences in different groups (P 0.05). The highest lysozyme activity was observed in the treatment fed on 200 mgLF diet which was significantly different from others (P 0.05). Treatment with the highest level of LF showed the highest level of bactericidal activity which was significantly different from others (P 0.05). Results showed that the lowest iron concentration in liver was in fish fed on 800 mg/kg LF which was significant (P 0.05). There were no significant differences in muscle iron concentration among groups (P 0.05). The highest intestine villa height was in 200 mgLF which was significantly difference from others (P 0.05). While no significant differences were observed in the total count of bacteria or lactobacillus content in the intestine of fish fed on different levels of LF in the diet (P 0.05). Heat stress (In 35?C , 12 hours)revealed that fish fed on 400 mgLF in diet were the most tolerant fish (P 0.05) while no significant improvement in the recovery rate after air exposure stress was observed (P 0.05). Finally it is understood that 200LF and 400LF treatments have positive effects on the most of physiological assays of African Cichlid and it is recommended to use them as an additive in the diet. Keywords : Growth, Hematology, Biochemical, Iron, Immunology, Intestine, Stress.