The generation and propagation characteristics of near-inertial waves(NIWs)generated spontaneously from a quasi-geostrophic anticyclonic mesoscale eddy in a rotating and stratified fluid were investigated by three-dimensional numerical modeling.NIWs are generated over a long time interval as a forced response to balanced baroclinic mesoscale eddies.For such eddies,NIW generation from balanced flow is an inevitable result as the evolution of eddies.Moreover,the baroclinicity of mesoscale eddies is an essential condition for this NIW generation mechanism.The spontaneously generated NIWs radiate horizontally toward the eddy center and propagate upward in vertical direction.The forcing of the NIWs moves downward along the eddy axis from the location of maximum temperature anomaly of the mesoscale eddy.The moving speed of the forcing is independent on the balanced mesoscale eddies but is determined by the ratio of buoyancy to inertial frequency.When the forcing reaches the bottom of the mesoscale eddy,the spontaneous NIW generation process terminates.NIW intensity in this spontaneous generation process is strengthened with the increase of the Rossby and Froude numbers.Further research to gain a solid understanding of the role of the Rossby and Froude numbers is necessary for the parameterization of spontaneous NIW generation from quasi-geostrophic mesoscale eddies in general circulation model.