NiTiNb shape memory alloy ingots were prepared by means of cold crucible vacuum induction melting method. Influence of this melting method on chemical composition and solidification microstructure of the alloy were studied. Losses of alloying elements during vacuum induction melting were evluated. Method for improving the accuracy of alloying element content was also advanced. The results show that higher heating power and repeated melting are benefit to sufficient alloying of different elements. The content of C and O increases with melting time and decreases with vacuum level, the influence of vacuum level is more notable than melting time. Lower cooling rate of the melt lead to the appearance of columnar zone. Besides, the size of columnar zone and shell zone in the ingt will continuously increase with the decrease of cooling rate. The splash which caused by the severe reaction of Ni and Ti during early period of melting will lead to heavier losses of the alloying elements. However, the accuracy of element content can be remarkably improved by adjustment of the weight for raw materials.