Great progress has been made in understanding the mesoscale eddies and their role on the large-scale structure and circulation of the oceans. However, many questions still remain to be resolved, especially with regard to the reproductivity and predictability of mesoscale eddies. In this study, the reproductivity and predictability of mesoscale eddies in the Northern SCS (NSCS), a region with strong eddy activity, are investigated with a focus on two typical anticyclonic eddies (AE1 and AE2) based on a HYCOM-EnOI Assimilated System. The comparisons of assimilated results and observations suggest that generation, evolution and propagation paths of AE1 and AE2 can be well reproduced and forecasted when their amplitude > 8 cm, although their forcing mechanisms are quite different. However, when their intensities are less than 8 cm, the generation and decay of these two mesoscale eddies cannot be well reproduced and predicted by the system. This result suggests, in addition to dynamical mechanisms, the spatial resolution of assimilation observation data and numerical models must be taken into account in reproducing and predicting mesoscale eddies in the NSCS.