An experimental investigation is conducted to determine the effect of rheological properties (viscoelasticity) on the air-blast atomization of coal water slurry. In air-blast atomization, aerodynamic force causes the liquid to deform and breakup. To observe breakup morphology of coal water slurry atomization, a high speed digital camera is used at various operating conditions. In this test, primary atomization is the condition that a cylindrical liquid jet surrounded by a coaxial annular airflow, and secondary atomization is the process that a liquid drop encounters a continuous air jet. The results show that the viscoelasticity of coal water slurry has great influence on the breakup morphology, breakup length, frequency characteristics. The corresponding correlations for these characteristics also are developed. (C) 2014 Elsevier B.V. All rights reserved.