We applied EBZM(electron beam zone melting)method to develop LaB6-ZrB2 eutectic in -situ composite for use as turbine blade material that can withstand 1650C or higher.We used EBZM method to implement small melting zone length and big thermal gradient,which were conducive to better structure and mechanical properties.The sample of LaB6-ZrB2 eutectic in -situ composite was prepared in two steps. Firstly,the primary rod was prepared by electric arc melting method, by which the rod could be made nearly fully dense. Secondly, the rod was recrystallized by EBZM method. The main results are as follows:(1) By readjusting the composition and controlling the solidification process properly,we obtained LaB6--ZrB2 eutectic in situ composite,with LaB6 as matrix and with uniformly distributed unidirectional ZrB2 whiskers(Fig.1 ).(2) We obtained two types of off -eutectic mlcrostructure.In hypoeutectic structure,LaB6 is primary phase and part of it is rectangular in shape(Fig. 2a).In hypereutectic structure, ZrB2 is primary phase,which has three different shapes:whisker -like, granular,petal-like(Fig.2b).(3) As the solidification rate increases,the diameter of whiskers and the spacing of whiskers decrease,the number of whiskers per unit area increases and reaches up to 108/cm2. Theoretical expectation is that this microstructure will increase the strength and the fracture toughness of in -situ composites used as structural components.