Multicanonical molecular dynamics (McMD) simulation is an enhanced conformational sampling method. For more accelerated sampling, we examined a trajectory-parallelization method, which trivially integrates multiple McMD trajectories into one. This method decreases communications between computing nodes largely. We applied this method to conformational sampling of a seven-residue peptide in explicit water. Physical quantities converged well with those from a long McMD simulation in a wide temperature range. Thus, the integration can generate a canonical ensemble without performing the long simulation. The current method is useful for folding study of long polypeptides (proteins) in explicit water with massive parallelism. (c) 2009 Elsevier B.V. All rights reserved.