The article is devoted to the search for forms of single-tube resonators of high q-factor for vibration density meters of a liquid. In tube resonators, the source of energy loss is the reactive forces that occur during vibrations in the places where the tube is fixed. Therefore, the search for high-q resonator forms is reduced to finding ways to reduce the loss of mechanical vibration energy in the supports. The existing methods of synthesizing resonator forms – heuristic and electromechanical analogies - are analyzed. The advantage is given to the method of electromechanical analogies, as scientifically justified. An algorithm for synthesizing the shape of a high-q resonator is formed. Using the proposed algorithm, a generalized form of a high-q resonator is synthesized, which is a rigidly pinched tube at the ends, symmetrical with respect to the vertical axis of symmetry, with three sections – the Central one and two identical peripheral ones, differing in their mechanical parameters from the Central one. In particular, the form of a resonator in the form of a tube with a step-variable cross-section is proposed.