A study of pressure fluctuation signals in an impinging entrained-flow gasifier was undertaken using multifractal analysis. By applying the method of direct determination of the f(alpha) singularity spectrum, the values of different radial position pressure fluctuation signals' singularity spectra were calculated. It was found that the pressure fluctuation exhibited the multifractal characteristics, the comparison of the pressure fluctuation signals from "unstable operating condition" to "stable operating condition" suggests that the combustion system is characterized by a dynamical change from heterogeneity toward homogeneity, revealed by a loss of multifractality. Origin of multifractal phenomena of the pressure signal measured in the entrained-flow gasifier was interpreted in terms of the multiplicative cascade process. (C) 2006 Elsevier B.V. All rights reserved.