Abstract: Based on the allyI polyoxyethylene and styrene sodium sulfonate as the raw material, potassium persulfate (K2S2O8) as the initiator, a new polyether dis persant for coal water slurry was synthetized with the free radical polymerization and water as the solvent.The infrared spectrum and the thermal analysis method were applied to the surface features and analysis on the polymers. The synthesis conditions affected to the dispersed effect to the coal water slurry were investigated.The exp eriment results showed that the optimum conditions of the synthetized dispersant would be that the potassium persulfate content of the initiator was 4%，the mixing rati 0 of the allyl polyoxyethylene and styrene sodium sulfonate was 1.5: 1.0, the reaction temperature was 80。C and the reaction time was 4 h.when the dispersant applie d to the test of the Shenfu coal water slurry, the apparent viscosity measured with different density coal water slurry showed that when the coal water slurry quality fract ion reached at 70%, the apparent viscosity would be 968.33 mPa.s.Thus the dispersant would have a high disperse effect.