Abstarct: In recent years, an interest to the thermoelectric phenomenon has increased significantly due to its attractiveness. In fact, since the early 1990s, the study of this phenomenon in nanoscale and the use of nanostructures showed that the more we move towards structures with smaller dimensions, the more we will see a significant increase in the thermoelectric figure of merit. A review of previous studies shows that research in this area has led to promising results in recent years. In the present study, the thermoelectric properties of a quantum well wire have been investigted. The Lippmann-Schwingroe equation was used to calculate the electron transmission coefficients of the system. The Landauer approach was used to determine the thermoelectric coefficients. The results of calculations in GaAs quantum well wire system show the role of decrease in dimensionality in increasing the figure of merit. In addition, the change in the figure of merit of the system with changes in temperature, ermi energy and width of the quantum well wire has been investigated.