Abstract: in order to study the effect of various factors on the quality ofoculation in utra clean coal preparation process the response surface method( RSM ) was adopted to analyze and optimize those factors.Based on single facortests the mathematical modelof thee facos(stiring tinm ,stiring speed and dosage of agen)affected to yield and ash of ultra clean coal was built y three factors and three lsvels center combination experiment and Design Expet sofivare .The optimum produ:tion conditons offocculation was obtained byusing RSM to exrat and optimize the data caculated by the mathemacal mode.T he results showed that eff ct order ofactors on yield and ash was from lage to small as follws dosage of agen .tirin time tiring sped.The optimum technical conditons of he foculation preparationwere tiring time 2s min stiring speed 2 0o i min.dosage of agent .51 m L. Under these co dtons expected yield was 84.71%.ash was 0.82%acual eld was 3451%,ash was 0.83%.