The demand for high performance and safer fuels has led to an ever increasing interest on gelled fuels. Here we report the synthesis and characterization of gelled high-density fuels with low-molecular mass gellants (LMMGs). This LMMG is synthesized simply by one step reaction and shows excellent gelling ability with the critical gellant concentration less than 1 %. Scanning electron microscopy studies reveal that LMMGs self-assemble into fibrous structures and create a 3D network structure by crosslink of these fibers, which constructs the basic network of gel. The basic physical and thermal properties of gelled fuels such as gel transition temperature (T-G), density, centrifugal stability and heat of combustion were investigated. Thermal characterizations reveal that the gels are thermally reversible and the T-G increases with the concentration of gellant. Physical stability determined by the ratio of gel-liquid separation under high speed centrifugation shows that gelled quadricyclane (QC) and exo-tetrahydrotricyclopentadiene (HDF-T1) exhibit good physical stability. Rheological measurements show that the gels are shear-thinning and the viscosity increases with an increasing amount of gellant. The viscosity of gelled QC is the highest among four gelled fuels, followed by gelled HDF-T1. The strain sweep tests and frequency-sweep tests show that gelled QC also has superior mechanical strength while the gelled kerosene (RP-3) has the lowest strength. Gel with higher strength has a higher viscosity and better physical stability due to a more stable internal structure and stronger resistance to deformation.