Soot nanostructure can reflect the gas-phases species contributing to its formation. In previous studies of soot from a commercial gas turbine engine (GE CFM56 2C3) burning petroleum-derived and synthetic-based fuels, the soot nanostructure exhibited a progression associated with fuel compositions and engine conditions. In this study, two main parameters -adiabatic flame temperature (1600 & 2000oC) and fuel/air equivalence ratio (2.0 & 2.2) were varied to test their relative impact on soot nanostructure formation The soots were collected from the flat flame burning the petroleum based -JP-8, synthetic -FT, and the surrogates -Iso-Octane/n-Dodecane, m-Xylene/n-Dodecane, n- Heptane/n-dodecane, and n-Dodecane fuels on a McKenna burner. Images from highresolution transmission microscope (HRTEM) show that with higher adiabatic flame temperature and lower equivalence ratio contributes more fullerene- and graphitic-like carbon lamellae to the soot. Notably soots from synthetic-FT, and aliphatic -n- Dodecane fuels exhibit significant nanostructure at each tested condition and no progression with flame conditions.