1.The general event horizon formula of black hole is given from null hypersurface equation.
从零曲面方程出发,导出了黑洞视界面的普遍公.
2.In this paper , a rigidity theorem of hypersurface in real space form will begiven.In addition, we obtain rigidity theorems of submanifold in sphere which improvethe result of Hou and Xu.