Economic value of the rice product is determined by the quality of rice after paddy conversion operation to white rice. Conversion Coefficient and crack percent are two important indices for determining the quality of rice after conversion operation that type of dryer used is effective on level of these indices. In this study effect of air temperature was studied in four levels (40, 45, 50 and 55oC); final moisture in three levels (8-10, 10-12, and 12-14%) and rice variety in three levels (Tarom-domsiah, Hashemy, Shirudy) on crack percent and conversion coefficient during the drying in a fluidized bed dryer. Experiments were conducted in the factorial design with three replications and three factors 3×3×4. Results showed that conversion coefficient of Tarom-domsiah, Hashemi and Shiroodi varieties reduced with increasing of moisture at all four temperature levels. In order to dry rice, temperatures 40oC and 50oC for Tarom-domsiah variety and temperature 55oC for Shiroodi variety lead to the best conversion coefficient. Crack percent of Hashemi variety increases with rising of drying temperature but crack percent of Shiroodi variety is reduced. Minimal crack percent of Tarom-domsiah, Hashemi and Shiroodi varieties is gained at temperatures (45oC and 50oC), 45oC and 55oC respectively. Hence, it is recommended to use temperatures mentioned for drying of these varieties in order to obtain minimal crack content.