To find the application of tri-s-triazine-based compounds, the geometric structures, electronic topologies, heats of formation, and relative specific impulses of tri-s-triazine and its nitrogen isoelectronic equivalents and decomposition of C3N10 have been studied by quantum chemical methods. The results reveal that all these species have a rigid planar structure and a conjugation system over the tricyclic ring, which is beneficial to their stabilities. The molecular electrostatic potential analysis for all the species shows that the central region of the ring has a very strong positive electrostatic potential, which suggests that these heterocyclic rings should be applicable as an anion recognition module in cyclophane chemistry. Along with the replacement of the CH groups by nitrogen atoms in the tri-s-triazine molecule, the heats of formation and relative specific impulses for the substituted products increase substantially. This result suggests the equivalent c is a good candidate for high-energy-density material.