Calmodulin (CaM) is a major cytoplasmic Ca2+ receptor and performs a multiplicity of functions in the cell. By using GFP-CaM fusion protein, we have studied the detailed dynamic redistribution of CaM during cytokinesis in HeLa cells. CaM associates with midbody in late cytokinesis phase. When the cells were treated with Ca2+/CaM inhibitor W7, the dissolving of the midbody was delayed. Moreover, we have found that gamma-tubulin colocalized with CaM at the midbody during cytokinesis. W7 treatment could affect the dissociation of gamma-tubulin from midbody. These results suggest that CaM may involve in the regulation of midbody microtubules disassembly and may thus affect the completion of cytokinesis.