CIPK (CBL-interacting protein kinase) interacts with calcium sensor CBL (calcineurin B-like protein). It was proved to play important roles in responding to stresses and regulating certain developmental processes in plants. Here, a recombinant plasmid was constructed for prokaryotic expression analysis for ZmCIPK31 obtained in this study. The results showed that the predicted target protein could be induced in the recombinant plasmid transformed E. coli BL21 strain cells. Protein solublility analysis proved the target protein was soluble. Thus, the purified soluble target protein was obtained by being loaded onto an amylose resin column, which can be used for further protein kinase assay. Meanwhile, a 2189 bp DNA fragment, upstream of the putative translation initiation site (ATG) of the gene, was obtained as ZmCIPK31 promoter region. A promoter motif search of this region showed that there were not only TATA-box and CAAT-box, but also motifs related to light, stress, development, auxin and others. Under polyethylene glycol (PEG) stress, the expression of ZmCIPK31 was induced. Moreover, the expression pattern of ZmCIPK31 in shoots was different from that in roots.