Abstract: Physiological condition is one of the most important characteristic used for evaluating single individuals, populations and fish stocks in general. The data on a number of physiological indicators of bream the Gorky water reservoir were presented. Amount of moisture, dry matter in the muscular tissue was determined of using two-stage determination of total moisture. Simple lipids were determined by extraction with petroleum-ether. The analysis of the results suggests that the indices of water, dry matter and simple lipids content in muscular tissue of mature males, females and juvenile individuals of bream were close. Decrease of water amount in the muscle tissue, increase of dry matter end lipids takes place along with bream ageing.