Abstract: The impacts of aromatic compounds on antiknock performance, vapor pressure and distillation of aviation gasoline base fuel were systematically studied. The experimental results showed that aromatic compounds such as aniline, mesitylene, toluene and cumene could effectively improve basic fuel antiknock performance. With the same blending concentration, aniline was the strongest antiknock improver. Experimental results also showed that motor octane number (MON) decreased with increased o-xylene concentration in fuel even though the MONs of o-xylene and cyclopentane were higher than that of base fuel. Moreover, base fuel vapor pressure linearly decreased with increased aniline, toluene or p-xylene concentration. The distillation temperature for 50 vol% evaporated and 90 vol% evaporated were out of specification even though the final boiling points for m-xylene and base fuel mixture and for mesitylene and base fuel mixture were within standard limit. Further study showed that the MON increment caused by mixing aviation gasoline base fuel with several aromatic compounds was equal to the sum of MON increment caused by mixing base fuel with single aromatic compound individually.