Under the COMPASS (condensed-phase optimized molecular potentials for atomistic simulation studies) force field, the molecular dynamics (MD) simulation was applied to first-to-third generation nanosize amine-based and butanediamine-based graphite/dendrimers composites. In this paper, we briefly introduced the constructive process of the composite system by means of MD simulation. The stability and mechanism of six intercalation composites were studied with microcosmic figure and variational energy under the invariable NVT ensemble. The energy variety was analyzed using the radial distribution function. The results indicate that the bulk of the dendrimer is small, the graphite layer is easy to bend and its systematic total energy is higher, which lead to the instability of the composite system. Therefore, the 3G dendrimer is the most stable system.