This study aimed to investigate the effect of cooling and chilling on the physicochemical and quality attributes of two fish species: Nile Lebeo (Labeo niloticus) and Sharp Tooth Catfish (Clarias gariepinus) that inhabit in Nasser Lake . Fish samples were preserved by cooling at 4°C and chilling by crushed ice in a ratio of 1:2 (fish: ice) for four days and freeze storing at -18 °C for (12) weeks. Samples were taken every two weeks for analysis. The chemical and physical change such as proximate chemical composition, protein fractions, fatty acid composition, amino acid composition, and thiobarbituric acid reactive substances (TBA) were examined in fresh, after cooling and chilling (zero time) and during freeze storing of fish samples. The obtained results revealed that the moisture, crude protein, myofibrillar, and (TBA) contents were significantly increased (p≤0.05) during storage, while the crude lipids, ash and sarcoplasmic contents were decreased for both of fish samples. However, fatty acids, amino acids composition and pH showed highly significant (p≤0.05) increasing trend in both the samples. Generally; cooling process of fish at 4ºC caused comparatively lower changes than chilling process.