Introduction. It was studied the lipid composition of the blood plasma of rats under the impact of a hyper cholesterol diet with a high fat load. It was carried out the prevention of disturbances in blood plasma biochemical parameters with a lipid complex from the tunic of the marine hydrobiont Halocynthia aurantium. Materials and methods. The experiment was carried outwith outbred male rats weighing 200 ± 3 g.The experimental model of a hyper cholesterol diet with a high fat load with the development of dyslipidemia was set up by feeding the animals with ahigh fat diet consisting of 2% cholesterol and 20% beef fat from the total diet. The animals were divided into the following groups of 10 rats each: group 1 - control (standard diet), group 2 - dyslipidemia (hypercholesterol diet with high fat load), group 3 - dyslipidemia + lipid complex from ascidia. Results. It was shown that the influence of the diet was accompanied by an increase in the amount of total lipids in the blood plasma of rats, cholesterol, low-density lipoproteins (LDL), as well as a decrease in total phospholipids and high-density lipoproteins (HDL), which is considered as an indicator of the formation of dyslipidemia. The contents of phospholipid lysofractions increased due to the activation of phospholipases. The amount of fatty acid esters and cholesterol esters decreased, which indicates the inhibition of esterification processes. The imbalance in the phospholipid spectrum of blood plasma occurred: the amount of metabolically active fractions required for the functioning of membrane-bound enzymes decreased. The addition of a lipid complex from the tunic of ascidian purple into the diet was accompanied by a pronounced prophylactic effect, which manifested itself in the normalization of the studied biochemical parameters. The lipid complex containing a wide range of “sea” phospholipids and polynonsaturated fatty acids of the n-3 type is an important basis for application as prophylactic in the conditions of a hypercholesterol diet with a high-fat load. Conclusion. Application of the lipidic complexes containing the “sea” lipids allocated from a tunic of the ascidian purple can be useful and perspective at a dislipidemiya and a hypercholesterolemia that will allow to carry out effective prevention of violations of metabolic reactions at influence of hyper high-calorie food.