Abstract: Under the COMPASS(condensed-phase optimized molecular potentials for atomistic simulation studies) force field, the molecular dynamics(MD) simulation was applied to on 1~3 generation amine-based and butanediamine-based graphite/dendrimers nano-size composite materials. The process of construction and the details of molecular dynamics simulation of the composite system were introduced. 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 by 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. This leads to the instability of the composite system. As a result, the 3G dendrimer is the most stable system.