The autoignition and subsequent flame propagation of initially nonpremixed turbulent system have been numerically investigated. The unsteady flamelet modeling based on the RIF (Representative Interactive Flamelet) concept has been applied to account for the influences of turbulence on these essentially transient combustion processes. In this RIF approach, the partially premixed burning, diffusive combustion and formation of pollutants (NOx, soot) can be consistently modeled by utilizing the comprehensive chemical mechanism. To treat the spatially distributed inhomogeneity of scalar dissipation rate, the multiple RIFs are employed in the framework of Eulerian Particle Flamelet Model approach. Computations are made for the various initial conditions of pressure, temperature and fuel composition. The present turbulent combustion model reasonably well predicts the essential features of autoignition process in the transient gaseous fuel jets injected into high-pressure and high-temperature environments. (C) 2004 Elsevier Ltd. All rights reserved.