A substrate for multi-chip stacking and a multi-chip stack package utilizing the substrate and its applications are disclosed. The substrate comprises a first wire-bonding finger, a second wire-bonding finger, a trace configured for electrical transmission and a loop wiring on a same surface. The first wire-bonding finger and the second wire-bonding finger are adjacent each other and to a die-attaching area of the substrate. The loop wiring connects the first wire-bonding finger with the second wire-bonding finger in series and connected to the trace. The loop wiring can be selectively broken or not when at least two chips are stacked on the die-attaching area and electrically connected to the first and second wire-bonding fingers respectively. Accordingly, the chips can operate respectively and independently without mutual interference if one of the chips is fail. Moreover, there is merit to apply the multi-chip stack package utilizing the substrate because it can be repaired after molding and without removing any bonding wire during semiconductor packaging processes.