§1.IntroductionIn[1],R.SchoenandS.T.Yanusedharmonicmaptostudythetopologyofanon-compactcompletestablehypersurfaceinamanifoldofnon-negativecurvature.Essentiallythemethodistoprovefirstthenonexistenceofsomekindofnonconstantharmonicmapandthentodrawtherelativeconclusionsconcerningthetopology.Suchnonexistencetheoremshavebeenobtainedin[3]and[4]incaseswheretheconcernedmanifoldsarecompact.Theaimofthispaperistostudythenon-compactcompletecase.Ourmainresultscanbestatedasfollows.
