Based　on　the　connection　between　macroscopic　and　microscopic　characteristics　of　carbon　black　filled　rubber　composites,　Representative　Volume　Element　(RVE)　containing　one　single　particle　has　been　proposed,　and　three　dimensional　cubic　RVE　has　been　established　to　study　and　analyze　the　macroscopic　mechanical　properties　of　the　carbon　black　filled　rubber　composites　by　the　micromechanical　finite　element　method.　The　research　shows　that　the　stiffness　of　the　composite　is　increased　with　the　increase　of　the　volume　fraction　of　carbon　black　filler　particles.　By　comparison,　it　is　shown　that　the　results　of　the　predictions　on　the　stress-strain　behavior　of　the　rubber　composite　made　with　the　cubic　RVE　numerical　models　containing　one　spherical　particle　are　in　good　agreement　with　the　experimental　results　for　seven　and　fifteen　percent　carbon　black　filler　content,　but　there　is　some　discrepancy　between　them　for　twenty-five　percent　carbon　black　filler　content.　The　results　of　the　predictions　on　the　stress-strain　behavior　of　the　rubber　composite　made　with　the　cubic　RVE　numerical　models　containing　one　cubical　particle　are　higher　than　the　experimental　results,　and　the　higher　the　carbon　black　filler　content,　the　greater　is　the　discrepancy　between　them.