Autophagy begins with the nucleation of phagophores, which then expand to give rise to the double-membrane autophagosomes. Autophagosomes ultimately fuse with lysosomes, where the cytosolic cargoes are degraded. Accumulation of autophagosomes is a hallmark of autophagy and neurodegenerative disorders including Alzheimer's and Huntington's disease. In recent years, the sources of autophagosome membrane have attracted a great deal of interests, even so, the membrane donors for autophagosomes are still under debate. In this review, we describe the probable sources of autophagosome membrane.