It is important and necessary to make further studies on comprehensive fertility estimation in urban forest soil which plays an important role in the sustainable development of urban forest and ecosystem. In this paper，modified Nemoro Index(Q) was used to assess the fertility quality of urban forest soil with the 6 indicators of soil bulk density,texture,pH,organic matter,available potassium，and cellulase activities in Nanjing City. Results showed that the range of Q of urban forest soil was 0. 85-1.51,the mean value was 1 .19±0.17,and the percentage of soil samples in the middle level of 1.0≤Q<1.5 was 90. 91>.Soil fertility Q in suburban forest and mixed forest of tree，shrub,and grass were comparatively high，while that in road green belt and lawn was just the opposite. It is concluded that the fertility of urban forest soil in Nanjing City is in middle-low level and needs to be restored immediately,and the lawn is not the ideal material for soil fertility restoration.