In order to obtain the test data and influence of aromatic volume fraction on smoke emission，the smoke number test scheme of a turboshaft engine was designed. Aromatic hydrocarbons volume fraction of kerosene from different production regions was compared and analyzed. By adding toluene(C6H5CH3) to RP-3 kerosene

different volume fractions of aromatic hydrocarbons could be gained.The influence of aromatic hydrocarbon volume fraction on smoke emission was studied in domestic aeroengine field. The correlation of smoke number (SN) with concentration index (CI) was fitted according to the measured smoke number. Test results showed that the smoke emission index increased with the power state of turboshaft engine

and the smoke number was less than 40

which was superior to design requirements when turboshaft engine adopted baseline fuel. The increase of 3 percent in aromatic hydrocarbon volume fraction can lead to increase of 6 percent in smoke number. The test has provided an effective method for measurement and prediction of exhaust smoke and also beneficial experience and alternative fuels for suppressing smoke of turboshaft engines.