Aging induces a decline in both memory and learning ability without predisposing an individual to diseases of the central nervous system, such as dementia. This decline can have a variety of adverse effects on daily life, and it can also gradually affect the individual and the people they are surrounded by. Since recent evidence indicated that placental extract has effects on brain function such as memory, we hypothesized that placental extract could ameliorate the age‐associated reduction in cognitive function in aging. Here, we investigated the effect of new modified porcine placental extract (SD‐F) on memory ability in aged mice at both the behavioral and molecular levels. Our results revealed that SD‐F significantly enhanced memory ability in the object recognition and object location tasks in a dose‐dependent manner in aged mice relative to controls. The numbers of Nissl‐positive cells in the hippocampal cornu ammonis 3 (CA3) and dentate gyrus (DG) regions were increased in SD‐F‐treated aged mice relative to controls. RNA‐seq analysis of the hippocampus of aged mice identified 542 differentially expressed genes, of which 216 were up‐regulated and 326 were down‐regulated in SD‐F‐treated mice relative to controls. Of the 216 up‐regulated genes, we identified four characteristic genes directly related to memory, including early growth response protein 1 ( Egr1 ), growth arrest and DNA‐damage‐inducible, beta ( Gadd45b ), NGFI‐A binding protein 2 ( Nab2 ), and vascular endothelial growth factor a ( Vegfa ). These results suggest that the efficacy of SD‐F involves upregulation of these genes.