The herbal extract(YMT_02) is a modified extracts from Yukmijihwang-tang(YMJ) to promote memory-enhancing. The YMJ extracts has been widely used as replenishing yin and tonifying the kidneys herbal medicine for hundred years ia Asian countries. The purpose of this study is to: 1) quantitatively evaluate the memory-enhancing effect of YMT_02 by passive avoidance test, 2) statistical evaluation of candidate gene expression (pentraxin. PEP-19, transthyretin) in rat hippocampus. The hippocampi of YMT_02 and control group were dissected and mRNA was further purified. After synthesizing cDNA using oligo-dT primer, the cDNA were applied to Real Time PCR. The results were as follows : 1) passive avoidance test showed enhancing memory retentin by YMT_02 treatment, 2) expression of pentraxin, that accelerate degenerating of neuronal cell, was significantly decreased, 3) the mRNA of genes that has been known to be associated with protecting neuronal cell degeneration, such as PEP-19 and transthyretin, were significantly increased upon YMT_02 treatment. From above results, the administration of YMT_02 which tonify the function of Kidneys could enhance the ability of memory and learning. In addition, the administration of YMT_02 enhance memory retention through modulating particular gene (pentraxin, PEP-19, transthyretin) expressions in hippocampu.