To maintain the traditional notion of global serializability in multidatabase systems has been recognized as one of difficult problems due to the autonomy of participating local database systems. In this paper, we propose a global concurrency control algorithm based on the relaxed concurrency control criterion in distributed MDBs, which can be applied to applications in which the database integration has no effect on the integrity constraints. In the proposed algorithm, the process to determine whether a global transaction can be executed or not consists of intra-validation phase and inter-validation phase.