ABSTRACT The aim of this study was to investigate the effect of eight weeks endurance training on Apelin receptor gene expression in adipose tissue of old male rats.In order to conduct the study, 12 male rats were randomly divided into control and experimental groups for 20 weeks. The rats in the experimental group practiced on the treadmill for 8 weeks, 5 days a week with an intensity of 20 meters per minute (equivalent to 75 to 80 % of maximum oxygen uptake) for 60 minutes. After 8 weeks practicing, and 72 hours after the last practice session, adipose tissue samples were collected. Then, REALTIME PCR method was applied to identify the definite variables. Data analysis was conducted based on independence t-test in a significant level (p<0.05). The findings of this study revealed that Apelin receptor gene expression levels in the experimental group in compare to the control group indicated a significant increase after eight weeks endurance training (p<0.00). Increasing Apelin receptor mRNA in rats may possibly regulate the adipose tissue and increase unpaired protein expression to determine its role in energy metabolism