We examined by ultrasound shear wave elastography (SWE) changes of liver stiffness (LS) in three groups rats of different ages. LS measurement by SWE was performed on "Ultima PA" equipment ("Radmir", Kharkov, Ukraine) with a 10-5 MHz linear transducer. To assess the functional state of the liver at the same time we studied age-related biochemical and morphological differences in the liver. A valid LS determination (success rate of at least 60%) was observed in 96.6% animals of different age groups. We observed statistically significant increasing of LS between 3-month and 20-month rats (p = 0.010), but its value in each group do not exceed normal or reference range. In article discussed possible connection between age-related changes of LS and state of connective tissue elements, functional activity, hydration, etc. It is concluded that shear wave elastography may be a new objective biophysical method for obtaining information about the state of the liver stiffness of the liver tissue.