ChIPModule is a software tool for systematical discoveray of transcription factors and their cofactors from ChIP-seq data. Given a ChIP-seq dataset and motifs of a large number of transcription factors, ChIPModule can efficiently identify groups of motifs,whose instances significantly co-occur in the ChIP-seq peak regions. By discovering groups of co-occurring motifs, ChIPModule enables the systematic study of cofactors in ChIP-seq peak regions.