In this study with usage of morris water maze and reference memory technique, we used 10 male albino wistar rats. Five rats in control group and 5 rats in Reference memory group. After histological preparation, the slides were stained with PTAH staining for showing the Astrocytes. Present results showed significant difference in astrocytes number in CA1, CA2 and CA3 area of hippocampus between control and reference memory group. The number of astrocytes is increased in reference memory group. Then we divided the hippocampus to three parts: Anterior, middle and posterior and with compare of different area (CA1, CA2 and CA3) of hippocampus, we found that the increase of astrocytes number in posterior two-third of CA2 and CA3 is more than of it's number in the anterior one-third.