With the development of imaging and analytical techniques,the understanding of cells is becom-ing increasingly profound.Decades or even a hundred years after the discovery of classic membranous organelles,more and more membraneless organelles have been discovered.This review focuses on the discovery,distribution,and evolutionary conservatism of a new type of membraneless organelle,the cytoophidium,and explores the struc-ture,function,and application of cytoophidia and metabolic filaments.