A new Z-Matrix building matrix for Z-Matrix is proposed in this paper. There have been a considerable number of papers in the literature that have presented methods in building Z-Matrix for large-scale power system, however, those methods only emphasize on the relationship between bus voltage and bus current injection. This paper provides a new aspect to observe the relation of bus voltage, bus current injection and branch current of the network. The building algorithm is achieved by a simple search technique with two developed matrices considering the tree and link branches of network, and is very suitable to be programmable. Using these two developed matrices, the relations of bus current injection vs. branch current and branch current vs. bus voltage can be distinct, and it is very helpful for observing the variations in short-circuit analysis or contingency analysis. a numerical example shows that the proposed method can be applied for large-scale power system more effectively and systematically than the conventional method.