The influences of chemical segregation and phase transformation on liquid density variation during solidification of Ni-based supperalloy Inconel 718 were investigated using SEM and EDS.It was found that significant segregation in liquid prompts high Nb phase to precipitate directly from liquid,which results in the redistribution of alloy elements and liquid density in their vicinity.The term "inter-precipitate liquid density" is therefore proposed and this concept should be applied to determine the solidification behavior of superalloy Inconel 718.