Wind power generation is regarded as one of the most efficient ways to utilize renewable energy.With more and more wind power being integrated into high voltage transmission networks，the ways that wind power affects the small signal stability of power systems needs to be explained.A research based on the eigenvalue analysis is presented.The influence of dynamic characteristics of doubly-fed induction generator（DFIG）wind turbines in maximum power point tracking（MPPT）mode with or without virtual inertia control on the small signal stability of power systems is presented.The static power injection model can be used to analyze power system small signal stability.The conclusions are validated by simulation results.