Subcellular localization and function of MreB in Anabaena sp.PCC 7120 was investigated by using MreB-GFP fusion vector with a mreB promoter.Effects of A22 in Anabaena sp.PCC 7120 with a MreB-GFP were studied.The organization of MreB changes dynamically throughout the cell cycle.Treated with A22,the MreB-GFP protein can not aggregate normally.