A skeletal reaction mechanism of n-heptane combustion is developed and validated. The axisymmetric laminar co-flow diffusion flames of n-heptane/oxygen are simulated using the skeletal mechanism at elevated pressure, and the chemical reaction paths in three reaction zones of flame are presented. The n-heptane/oxygen flame height decreases from 8.8 to 5.6 mm with the increase of pressure from 0.1 to 2 MPa, and the Roper's formulation is not expected for the prediction of n-heptane/oxygen flame height. The maximum volume fraction of soot increases with pressure as f(v,max) proportional to P-2. The ratio of flame height to soot oxidation length of the n-heptane/oxygen flames is close to unity (1.037-1.121). (C) 2015 Elsevier Ltd. All rights reserved.