Large-sized precipitates are fatal to the thermal fatigue of H13 hot work die steel.Different amounts of Ti and/or rare earth(RE) were added in H13 steel during electroslag remelting to improve the element segregation and refine the large-sized precipitates.The results show that as Ti content increases from 0.0032 to 0.057 wt.％,the segregation of Cr,Mo and V becomes more severe.V-rich M(C,N) carbides are shorter,and their branches are denser in 3D observation.Moreover,the number density of V-rich M(C,N) carbides with a size less than 2 μm increases and that with other sizes decreases.In addition,Ti-rich MN nitrides with the size greater than 4 μm increases significantly at high Ti content.When RE content increases from 0.0051 to 0.036 wt.％,the segregation of main alloying elements is first weakened and then aggravated.Compared with that in RE-free H13 steel,V-rich M(C,N) carbides are less developed in 3D observation,and the change in number density is similar to that of Ti-modified alloys.After composite modification of 0.024 wt.％ Ti and 0.011 wt.％ RE,the segregation of alloying element and V-rich M(C,N) carbides are not significantly improved.