Experiments　were　performed　to　investigate　the　cool　down　performance　and　thermal　stress　in　an　aluminum　tank　versus　filling　elapsed　time　with　different　liquid　nitrogen　filling　methods,　i.e.,　the　bottom　axial　filling,　top　axial　filling　and　top　lateral　sprayer　filling.　Among　three　filling　methods,　the　top　lateral　sprayer　filling　obtained　the　fastest　cool　down　of　the　entire　tank,　however　accompanied　with　the　greatest　temperature　gradient　and　the　most　serious　thermal　stress.　Comparatively,　axial　filling　methods　led　to　more　uniform　temperature　distributions　and　lower　thermal　stress　levels.　The　peak　value　of　thermal　stress　for　a　top　axial　filling　was　about　75%　of　that　for　a　bottom　axial　filling　under　the　same　feeding　rate,　although　the　thermal　stress　distribution　patterns　were　similar.　The　thermal　stress　for　a　top　lateral　sprayer　filling　had　descending　values　in　the　lower　part　of　the　tank,　while　kept　at　a　much　higher　level　in　the　central　and　upper　part.　The　peak　value　reached　up　to　50%　higher　than　that　of　a　bottom　axial　filling.　This　work　could　be　beneficial　to　the　selection　and　design　of　filling　methods,　which　are　significant　to　cryogenic　tanks　in　consideration　of　filling　efficiency　and　safety.