We report the results of the preliminary isolation of two virus-like particles (VLPs) that are infectious to freshwater cyanobacteria from Lake Donghu,the largest urban lake in China,located in Wuhan City,Hubei Province. By light and transmission electron microscopy,we observed VLPs causing lytic infections in freshwater bloom-forming cyanobacteria,and we detected their infections by exposing the VLPs to 12 cyanobacterial strains,including Microcystis aeruginosa HAB1801 and Anabaena spiroides HAB1211. They were termed ‘Anabaena spiroides geminivirus-like (AsGV-L)' particles and ‘Microcystis aeruginosa corticovirus-like (MaCV-L)' particles,based on their ultrastructural morphological characteristics and host specificities.