Signature file is one of the efficient access methods for retrieval of text database. In a large database server, parallel device is utilized to achieve concurrent access. Efficient allocation of signature file on parallel device minimizes the query response time and is important in the design of large databases. In this paper, we investigate the design of parallel signature file. We propose a new dynamic allocation technique to distribute the signature file on parallel device. It is an improvement of previous approach of Fragmented Signature File. While Fragmented Signature File uses Quick Filter to distribute the partitioned frame signature file, the proposed Parallel Signature File uses a declustering technique. The proposed Parallel Signature File has some advantages. First, the qualified frame signature blocks are distributed more uniformly than Fragmented Signature Files. Second, the proposed scheme can also be used in dynamic environment. Performance analysis shows that performance of the proposed approach outperforms that of Fragmented Signature File and is not far from theoretical optimal response time.