Abstract The assembly of FtsZ plays an important role in bacterial cell division. Lipids in the bacterial cell membrane have been suggested to play a role in directing the site of FtsZ assembly. Using lipid monolayer and bilayer (liposome) systems, we directly examined the effects of cationic lipids on FtsZ assembly. We found that cationic lipids enhanced the assembly of FtsZ in association with an increase in the GTPase activity of FtsZ. The system consisting of lipid monolayer and bilayer (liposome) may mimic the bacterial membrane and therefore, the data might indicate the influence of bacterial membrane on the assembly of FtsZ protofilaments.