Abstract: The operations with large bit-width in residue to binary (R/B) conversion impairs the parallelism degree of residue number system (RNS). In this paper an scaling based R/B conversion algorithm and an RNS power of two scaling method are proposed. The analysis results show that the operation bit-width in the proposed R/B conversion is smaller than the maximum bit-width of radix in moduli set. Furthermore, the conversion results can be mapped into Tow's complement system (TCS) directly with arbitrary moduli set. As a result, the proposed R/B conversion algorithm can reduce the critical path in very large scale Integration (VLSI) circuits and improve the performance of VLSI.