Memory retrieval can trigger destabilization followed by reconsolidation for maintaining or enhancing original fear memory. Therefore, blockade of reconsolidation could weaken the original fear memory. The N-methyl-D-aspartate (NMDA) receptor and hippocampal neurogenesis play crucial roles in hippocampus-dependent memory processes, including reconsolidation. In this study, first, NMDA receptor signaling was downregulated by the genetic reduction of its co-agonist, D-serine, and the neurogenesis was ablated by focal X-ray irradiation on the hippocampus. We found that a progressive decrease in freezing following each retrieval, leading to an attenuation of remote contextual fear memory on day 28. Second, after conditioning, pharmacological approaches to simultaneously block D-serine signaling and inhibit neurogenesis, resulting in a similar suppressive effect on the remote fear memory. The present findings provide insights into the role of D-serine-mediated NMDA receptor signaling and neurogenesis in memory retrieval and the maintenance of remote fear memory, and provide a new strategy to improve exposure-based therapy for post-traumatic stress disorder(PTSD) treatment.