In this paper, an iterative soft-decision decoding algorithm is proposed for Reed-Solomon (RS) codes. The proposed decoding algorithm combines the concepts of adapting the parity-check matrix and informed dynamic scheduling. Before each iteration, the parity-check matrix is re-arranged according to the reliability of the codeword bits, meaning that the influence of the least reliable variable nodes on the decoding process can be reduced. Consequently, the important decoding messages can be scheduled to be updated first, and the reliability of the least reliable bits can be enhanced. The simulation results show that the proposed decoding algorithm can provide significant improvement in the error-rate performance. By using the proposed algorithm, a gain of 0.5 dB can be achieved compared to the conventional adapting belief propagation algorithm.