In this paper, we present an approach to synthesize multiple behavior modules. Given n DFGs to be implemented, the previous methods scheduled each of them sequentially, and implemented them as a single module. Though the method is appropriate for sharing the functional units, it ignored the following two aspects: 1) different interconnection patterns among DFGs can increase the interconnection area and delay of the critical path, 2) the sequential scheduling of DFGs has a difficulty in considering the effects on the other DFGs not scheduled yet. We show an efficient way to solve the problems using a selective grouping method and the extensions of the traditional scheduling methods. The experimentation reveals that the result obtained by the proposed method is better to reduce interconnection area and to meet the timing constraints than those obtained by the previous methods.