In this study, a jet propulsion JP combustor is studied numerically to investigate the combustor wall temperature influences on the soot characteristics emitted at its exhaust. There are a number of ways to control the combustor wall temperatures benefiting from different wall cooling technologies. Irrespective of using different high technology cooling systems, it is important to recognize how the wall temperature can affect the soot emission from one specific JP engine. Before examining the main combustor, it is important to assess the accuracy of the computational fluids dynamics (CFD) tool via solving a benchmark problem. In this regard, the predicted flame structure for the benchmark problem is compared with the corresponding data collected from the measurement. After ensuring the numerical accuracy of the CFD code, we proceed to evaluate the impact of combustor wall temperature on the soot emissions from the exhaust gases. The current numerical study is conducted in such a manner to implement different cooling system technologies. Then, the achieved results of thermal and soot characteristics for the JP-fueled combustor are carefully studied via inspecting the distributions of temperature, soot volume fraction, and soot particles diameter in the combustor. The current study reveals that the soot emission from the gas-turbine combustor mostly decreases with increases in wall temperature. © 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.