Abstract: The extruded rice was prepared by using brown rice,corn,glutinous rice and Bulgaria inguinans as raw materials in the present study.The key technology and process parameters in the development process were investigated.The basic operation process for extruded rice preparation was materials grinding,mixing and uniformity,modulation,extrusion,and drying.The mixed powder was extrusion puffed by double screw textruding and the physical property of grain powder had significant change after high temperature and high pressure treatment.The starch in the grain absorbed water and expanded to a hundredfold volume to form a viscous colloid which could connect other substance and accessory of grain to form a rice granule.The effect of extruded temperature,moisture content and screw speed on the quality of extruded rice was conducted through single factor experiments.The extrusion process was optimized by Box-Behnken Design Methodology and assisted by software Design-Expert 8.0.6.Results showed that under the conditions of screw speed 180 r/min,extrusion temperature 100℃ and moisture content 27%,the comprehensive score of the quality of Bulgaria inguinans Extruded Rice was 76.62,which was consistent with the predicted values.The prepared Bulgaria inguinans extruded rice products had aroma of rice and edible fungi,compact structure,good integrity,smooth,sticky and non-sticky teeth.Compared with natural rice,extruded rice had lower hardness and chewiness than that of natural rice,but the elasticity and viscosity was higher than that of natural rice.