By　measuring　the　magneto-capacitance　spectroscopy　of　an　n-type　InSb　metal-insulator-semiconductor　(MIS)　structure,　the　2-D　hole　subband　in　the　p-type　channel　of　the　InSb　MIS　device　was　investigated　under　different　magnetic　fields　at　1.2K.　The　results　show　that　the　on　set　energy　of　the　p-type　channel　depends　strongly　on　the　magnetic　field,　which　is　mainly　attributed　to　the　dependence　of　the　InSb　band　gap　energy　on　the　magnetic　field.