Abstract: The influence of the additional crackle ratio increment( ACRI) under different drying temperature,moisture removal of each drying passes( MREDP) and tempering time were studied,and the changes of paddy rice's microstructure were investigated by using of scanning electron microscope. The drying temperature,MREDP,tempering time and the interaction of the drying temperature and tempering time showed significant effects on the ACRI of rice( p < 0.01). The order of the influence of the aforementioned parameters on ACRI was the drying temperature > tempering time > MREDP. With the drying temperature of 65 ℃,3.00% MREDR and 3 h tempering,the starch granule's arrangement became loosen and the crack between starch strands increased. Under the drying temperature of 45 ℃,3 h tempering and 1.50% MREDP,the rice ACRI was 1.0%,and the drying rate was1.32 g H_2O·min~- 1,which could ensure the processing quality and improve the drying rate of paddy rice.