Purpose of the study — to compare the effects of modified fluid gelatin (MFG) solution and autologous blood on the acid-base status of the blood and cutaneous microhemocirculation in rats using an experimental model of acute blood loss. Material and methods. Experiments were carried out on male outbred rats weighing 300g to 400g. The animals were anesthetized by intraperitoneal injection of pentobarbital (45 mg/kg). An acute fixed-volume hemorrhage model was used (30% of CBV). Laser Doppler Flowmetry (LDF) was used to record microvascular blood flow in rat’s skin. The wavelet transform was used to determine the amplitude and frequency characteristics of blood flow oscillations (fluxmotion). The following parameters were determined: mean arterial blood pressure (BPm), mean blood flow (M); the maximum amplitude of blood flow oscillations (Amax) and the corresponding oscillation frequency (Fmax); the acid-base status of the blood; glycemia; hematocrit (Ht) and hemoglobin (Hb) levels. At the stage of reinfusion, the withdrawn blood was reinfused in the reference group. In the experimental group (Gelofusin), the animals received an infusion of a 4% solution of MFG (Gelofusin B. Braun Medical AG, Switzerland) in a volume equal to that of the blood withdrawn. To quantify the severity of hypoxia, the oxygen delivery index to the tissue under investigation (DtO2) was used. Results. At the posthemorrhagic stage, a decrease in BPm, M, DtO2 and Fmax was observed along with an increase in the Amax. The values of Hb, Ht, pH, pCO2 and BE were reduced with the development of compensated/subcompensated metabolic acidosis. At the reperfusion stage, the values of M and Fmax returned to the baseline in both groups. Amax did not differ between groups. Intergroup differences consisted of lower values of BPm, DtO2, Hb, Ht, BE and glycemia in the Gelofusin group. Conclusion. Blood replacement in the acute blood loss with an equal volume of MFG was accompanied by changes in investigated blood parameters that were comparable to those in reinfusion of autologous blood. M and Fmax values of both autologous blood and MFG were restored to the baseline.