Magnetocapacitance　spectroscopy　is　introduced　to　study　the　magnetic-field-induced　carrier　freeze-out　in　narrow-gap　semiconductors　(NGS).　By　using　this　experimental　method　the　magnetic-field-induced　carrier　freeze-out　in　an　n-type　InSb　sample　has　been　investigated　at　4.2　K　in　a　magnetic　field　range　from　0　to　7.0　T.　With　increasing　magnetic　field　between　2.0　T　and　7.0　T,　the　activation　energy　of　shallow　donors　in　the　sample　increased　from　about　1.0　meV　to　2.7　meV.　The　experimental　results　are　compared　with　both　theoretical　and　other　experimental　data.　Good　agreement　is　obtained　between　our　experimental　results　and　others,　while　discrepancies　still　exist　between　the　experiment　and　theory.