In this paper, two kinds of inorganic nanoparticles based on different manufacturing processes were used as stabilizers of coal water mixtures (CWMs). The size and shape of nano-stabilizers and their steady mechanisms were explained by study of TEM and zeta potential. The properties, zeta potential, rheology and the stationary stability of coal water mixtures made up nano-stabilizers and different coal samples were investigated. In order to achieve static repulsion and steric hindrance effects simultaneously, based on the weight proportion, two nano-stabilizers were compounded. Experiments have proved that the compound inorganic nano-stabilizer has an advantage over conventional stabilizer, such as carboxymethyl cellulose sodium salt (CMC-Na), and it can be developed as a new type of stabilizer. (c) 2006 Elsevier Ltd. All rights reserved.