The directionally solidified samples of an ultra-high temperature Nb-Si-Ti-Hf-Cr-Al alloy have been prepared with the use of an electron beam floating zone melting (EBFZM) furnace, and their microstructural characteristics have been analyzed. All the primary dendrites of Nb solid solution (Nbss), eutectic colonies of Nba, plus (Nb, Ti)3 Si/(Nb, Ti)5 Si3 and chains of (Nb, Ti)3 Si/(Nb, Ti)5 Si3 plates align along the growth direction of the samples. With increasing of the withdrawing rate, the microstructure is refined, and the amounts of Nbss+ (Nb, Ti)3 Si/(Nb, Ti)5 Si3 eutectic colonies and (Nb, Ti)3 Si/(Nb, Ti)5 Si3 plates increase. There appear nodes in the (Nb, Ti)3 Si/(Nb, Ti)5 Si3 plates. The directionally solidified samples of an ultra-high temperature Nb-Si-Ti-Hf-Cr-Al alloy have been prepared with the use of an electron beam floating zone melting (EBFZM) ​​furnace, and their microstructural characteristics have been analyzed. All the Primary dendrites of Nb solid solution (Nbss), eutectic colonies of Nba, plus (Nb, Ti) 3 Si / (Nb, Ti) 5 Si3 and chains of (Nb, Ti) 3 Si / (Nb, Ti) With increasing of the withdrawal rate, the microstructure is refined, and the amounts of Nbss + (Nb, Ti) 3 Si / (Nb, Ti) 5 Si3 eutectic colonies and (Nb, Ti) 3 There are nodes in the (Nb, Ti) 3 Si / (Nb, Ti) 5 Si3 plates.