Abstract: In order to clarify the influences of virtual synchronous generators（VSG） on the subsynchronous oscillations of grid-connected wind power systems, the full-order state-space model of the grid-connected wind power system with VSG is developed.After that, the damping characteristics of the VSG in the subsynchronous oscillation mode is quantitatively evaluated by adopting the oscillation frequency and damping ratio as the quantitative indicators, and the participation factor is calculated to obtain the sensitivity of the control parameters involved in VSG to subsynchronous oscillations. Finally, the validity of the modeling method and the accuracy of the mechanistic analysis are verified by the time-domain simulation. The results show that although the VSG weakens the influences of the inner-loop proportionality coefficient in the rotor-side converter on the subsynchronous oscillations,the coefficient exerts the greatest influence on subsynchronous oscillations, and the integral coefficient of the VSG excitation control imposes a higher influence on the subsynchronous oscillations than the damping ratio.