The comparative studies of Nile Tilapia (Oreochromis niloticus) and Nile Perch (Lates niloticus) were caught from Nasser Lake. We aim to find the association between freezing and protein fractions. The comparative studies of two species. Were investigated during storage at -18˚C for 6 months. The Protein and protein fractions for Nile Tilapia (Total protein, Myofibrillar, Sarcoplasm, Connective tissue and Denaturated protein) were studied during this period by freezing at -20̊ C freezing at -30 ℃ and the best results were at glazing with rosemary extract were noted that from ( (18.02,12.44,3.96,0.29 and 1.33%) to (16.27,10.33, 3.68, 0.30 and 2.78%), respectively. As for Nile perch from (21.54, 13.77, 5.40, .94 and 1.43%) to (18.50, 11.30, 3.43, 0.90 and 3.31%) at glazing, correspondingly. Chemical, physical parameters and fatty acids changed during storage were investigated. Also, the amino acids increased during storage period. From the results drawn from this study, we find that the freezing by glazing rosemary in maintaining the quality of the stored fish especially on the protein fractions.