65.417%。Taking particles of rice straw as material, using straw treated by alkali as binder, adopting the quadratic orthogonal rotation design, the effects of various pressure, the additive proportion of binder, the moisture content and the grain size of raw materials on the loose density and the dropping intensity of briquette fuels was studied. A mathematical model of experiment with four factors was established and analyzed by regress method in SPSS 13.0 and response method in Matlab 7.1. The results showed that the regression equation was significant. The optimum factors were as follows, the pressure was 32MPa,the additive proportion of bonder was 4∶1, the moisture content was 10%, and the grain size of raw materials was 4mm. Under this condition, the loose density reaches 1188g/cm3, and the dropping intensity reaches 65.417%.