Abstract: In order to improve stability of humic acid dispersant,using humic acid,formaldehyde and sodium sulfanilate,a new sulfonated amino humic acid was prepared by sulfomethylation and polycondensation reaction; described by IR,1HNMR etc.,the product was used for coal water slurry preparation in Binchang,in the meantime ability to slurry preparation,stability of coal water slurry,compound of coal and product were investigated. The results showed that this dispersant was superior to naphthalene one in dispersity,stability; especially at dosage of 0. 50%,coal water slurry up to concentration of 67% was obtained,with 705 m Pa·s apparent viscosity; when it stood 7 days,the water separation rate was only 4. 40% with a little soft precipitation; with increasing the amount of dispersant,the greater absolute value of Zeta potential,the better stability of coal water slurry.