The present study investigates the heat and mass transfer in the drying of sized yarn by using Luikov equation. The finite difference method is used to solve numerically the governing equation. The mass transfer rate in the drying process is influenced by environmental temperature and moisture. The Soret effect shows that the drying efficiency of sized yarn may be improved not only by increasing the temperature but also by decreasing the moisture content of air in the drying chamber. To check the accuracy of the present computational method, the drying process of timber has been solved and compared with previous results. The properties of starch was used in computing the drying process of sized yarn. The present study may help in finding the optimum conditions of the drying chamber as well as expanding the study to coupling of the drying process and the thermo-fluid flow dynamics in drying chambers.