Rice is one of the main food staple after wheat in the world. According to population growth and production limitations, one of the approaches is decrease in the processing losses at milling plants. Hence, the main purpose in rice industry is the processing with high quality. To achieve such a goal, it is necessary to dry fresh harvested rough rice immediately after harvest to prevent microbial and spoilage losses. Nowadays, multi-pass procedure is used to remove moisture from rough rice kernels. Between drying passes, tempering operation is applied to prevent kernel fissure and crack at subsequent milling stages. In this regard, determining the best drying conditions, the number of drying passes and tempering duration for quick drying operation, low energy utilization and high quality of rice production is vitally important. In this study, two different rice varieties namely, Shafagh (long-grain) and Sazandegi (medium-grain) were dried at high ( air temperature and relative humidity of 60°C and 17% ) and low (air temperature and relative humidity of 40°C and 12%) drying conditions at four drying durations to remove 1.5, 3, 4.5 and 6% moisture content from freshly harvested rough rice. It is predicted that drying of rough rice samples at high and low drying conditions will happen at rubbery and glassy states, respectively. Each drying batch was split into seven sub-samples which were tempered in sealed bags for 0 to 240 min in 40 min increments. Finally, all samples were dried to 12.5% (w.b.) moisture content, which is suitable for milling process. After whitening, the quality parameters including head rice yield ( HRY ), optical degree of milling determined by a milling meter ( DOM mm ), mass degree of milling ( DOM m ), optical compound index ( C.I mm ) and mass compound index ( C.I m ) were obtained for each sample and statistically compared. Factors included drying condition, drying duration, temrering duration and variety were splitted as drying condition as main factor, the others as secondary factors and they were arranged according to completely randomized design. Results showed that variety, drying condition, and drying and tempering duration had a significant effect on all quality parameters (P 0.01). For both varieties and both conditions, the HRY value decreased as drying duration increased. Also the high temperature drying condition resulted in higher loss in HRY as compared to the low drying condition. Results for both varieties revealed that at low drying condition, applying tempering operation did not have a significant effect on Keywords : Degree of milling, drying, glass transition, head rice yield, tempering.