One of the perspective directions of search of the tests both for the estimation of a degree and prediction of biological consequences of an action of the ecologically unfavorable factors for organisms is the investigation of a state of process of lipid peroxidation (LPO) due to the high sensitivity of parameters of the LPO regulatory system to action of damage factors of the physical and chemical nature. The aim of this work was the investigation of the distant biological consequences of combined effect of the low toxic chemical agents at low doses (surfactant, Tween 80, and acetone) and X-rays in sublethal doses (4 and 5 Gy) on the state of LPO regulatory system parameters in tissues of the line Balb/c mice. The following parameters were analysed: 1) Peroxide amount mount in lipids of the animal tissues and blood plasma and content of the substances reacting with 2-thiobarbituric acid (TBA-RS); 2) composition of lipids in mice liver; 3) radiobiological consequences of a combined effect of the low toxic chemical agents and X-rays at doses 4 - 8 Gy. It was found the direct correlation between the TBA-RS content in homogenate and peroxide amount in lipids of mice liver in groups of control mice both for the individual animals within group and the average values between different control groups and also the reverse correlation between the ratio of the sums of the more readily to more poorly oxidizable fractions and the ratio of phosphatidyl choline to phosphatidyl ethanolamine content in phospholipids of mice liver in control groups. The reversal of direction of correlation between the TBA-RS content in homogenate and peroxide amount in liver lipids was revealed after single administration of 0,3 % solution of Tween 80 in 10 % aquatic acetone within 1 month. The direct correlation between the TBA-RS content in homogenate and peroxide amount in liver lipids was saved only for the average level of values in the mice liver with a correlation coefficient R=0.998 ±0.002 after radiation at dose 4 Gy within 1 month. The reversal of direction of interrelation between the TBA-RS content in homogenate and peroxide amount in lipids of a liver of the irradiated mice was revealed after combined effect of the low toxic chemical agents and X-rays when the dose was 5 Gy. The correlation between generalized parameters of phospholipids composition was saved by combined effect of the Tween 80, acetone and X-rays at sublethal doses within 1 month, however scale of correlation substantially differs as compared with control: the coefficient of linear regression is decreased by factors 1.4 – 2.7 at dose 5 Gy and by factors 2.0 – 3.1 at dose 4 Gy in groups of survival mice after irradiation. The gain of radiobiological consequences of administration of Tween 80 in aquatic acetone before irradiation was revealed as compared with the action of the single irradiation. The absence of a linear dependence biological consequences on the state of LPO regulatory system parameters in animal organs was found. The analysis of the obtained experimental data make possible to assess biological consequences of action of the different nature factors for animal groups by the scale and direction changes of interrelations between the interconnected in norm parameters of LPO physicochemical regulatory system in their tissues.