The integration of large amount of wind power into a power system imposes a new challenge for the secureand economic operation of the system. It is necessary to investigate the impacts of wind power generation on the dynamic behavior of the power system concerned. This paper investigates the impacts of large amount of wind power on small signal stability and the corresponding control strategies to mitigate the negative effects. The concepts of different types of wind turbine generators(WTGs) and the principles of the grid-connected structuresof wind power generation systems are first briefly introduced.Then, the state-of-the-art of the studies on the impacts of WTGs on small signal stability as well aspotential problems to be studied are clarified. Finally, the control strategies on WTGs to enhance power system damping characteristics are presented.