In the article, pulsating fluid flows in tubes with changing walls, which are of great importance in biological mechanics, in particular, in the flow of blood in the arterial vessel, are investigated. The solution of the problem obtained formulas for the distribution of pressure gradient, velocity and flow rate. Impedance method analyzed the increase in hydraulic resistance depending on the frequency of oscillation. It was found that with large values 2 of hydraulic resistance grow with growth 2 . For crowding out the same flow rates, for small and with large values of the vibrational number or frequency, the energy input is different. Since for small values of the oscillatory number, fluctuations in the flow rate of the fluid fluctuate in the same phase with the oscillation of the pressure gradient, and for large values of this number, the oscillation of the phase of the fluid flow is shifted by 0 90 degrees ELECTRONIC JOURNAL OF CENTRAL ASIAN PROBLEMS OF MODERN SCENCE AND EDUCATION. MARCH, 2019-I ISSN 2181-9750 11 than fluctuations in the pressure gradient. In addition, for large values of the vibrational number, a tenfold size increases the maximum amplitude of the pressure gradient, relatively, than at low frequencies. This feature leads to an increase in the energy cost of pumping fluid due to wall oscillatio
