n the present study, drying of sweet potato occurred only in the falling rate stage. The values of calculated effective diffusivity for drying at 50, 60, 70, 80 and 90 °C of air temperature and 1.5–5.5 m/s of air flow rates ranged from 1.26 × 10−9 to 8.80 × 10−9 m2/s. The effective diffusivity increased as flow rate and temperature increased. The activation energy for moisture diffusion was found as 11.38 kJ/mol, comparable with the reported values of various food materials. Page's empirical model showed a good fit curves than the first order kinetics of Henderson and Pabis model.