A  study  was carried  out  to  test  and  evaluate  the  drying  behavior  of  wheat grain  using  a  thin layer dryer  with controlled air temperature and relative humidity dryer. The studied parameters included four different levels of drying air temperature (50, 55, 60 and 70°C) and four levels of air relative humidity (30, 40, 50 and 60%). All the experimental runs were conducted at constant air velocity of (0.23 m/sec). The drying behavior of wheat grain during the drying process was simulated using three different thin layer drying models (Lewis's1921 Henderson and Pabis's 1961 and Page 1949 equations). Final quality of the dried wheat grain was also determined. The results show that, drying rate of wheat grain increased with the increase of drying air temperature while, it was decreased with the increase of relative humidity. All  studied  models  could  describe  the  drying  behavior  of  wheat grain .  However page model considered the most proper for describing the drying behavior of wheat grain in terms of higher values of (R²) and lowest values of (SE).