Abstract: The stability of emulsion for sulfuric acid and hydrocarbon was evaluated by Turbiscan Lab dispersion stability analyzer. The effect of operating variables, including composition of the sulphuric acid, time of agitation, severity of agitation, volumetric ratio of acid to hydrocarbon, and various hydrocarbons on the dispersion system stability were investigated. The results show that the fresh concentrated sulfuric acid can only make a small amount of n-heptane dispersing into sulfuric acid, while the waste acid can make n-heptane fully spread in waste sulfuric acid to form emulsification. When acid-hydrocarbon emulsion reaches balance, little effect of increasing mixing time on emulsion is found. And the higher the stirring speed and the higher acid-hydrocarbon ratio, the more stable of the emulsion; Different hydrocarbons and concentrated sulfuric acid form the emulsions with different stability. The stability of the emulsion consisted of isooctane and concentrated sulfuric acid is best, petroleum ether is the next. The stability of the emulsion formed by n-heptane and concentrated sulfuric acid is the worst.