Abstract: Suspensions of pulverized coal in fuel oil can be stabilized by treating fuel oil with an oil soluble polyamine containing at least two amino groups (or a polyamine which is rendered oil soluble upon reaction with suitable acid), then adding with agitation the desired amount of pulverized coal to the treated fuel oil and finally stabilizing the mixture by adding an oil soluble polycarboxylic acid containing at least two carboxyl groups in an amount sufficient to stabilize the coal-fuel oil mixture.Suitable amines may be selected from the group consisting of N-alkyl 1,3 diamino propanes and higher N-alkyl amines having more than two amino groups.Suitable acids may be selected from the group consisting of polymerized fatty acids and alkenyl polycarboxylic acids.