Global warming and climate change due to anthropogenic carbon dioxide(CO) have aroused significant concerns at the global scale due to rapid economic growth in industries and other fields. Therefore, COcapture, use, and storage have become particularly important. In this review, general background and methods for COcapture and separation, in particular, on ionic liquids(ILs)-based solvents and materials, are discussed. Comprehensive surveys of ILs for COabsorption are presented, which focused mainly on experimental researches, and then the concept is extended to functionalized absorbents and recent developments for COcapture. Major advantages and disadvantages of amines-based and ILs-based absorbents are discussed in this review. Solutions of traditional amines(MEA, MDEA, DEA, AMP, PZ, etc.) and ILs(conventional ILs, functionalized ILs, etc.) are summarized.Moreover, research progresses on COseparation are also introduced focusing mainly on amines and ILs-based membranes(e.g. supported amines membranes, SILMs). Futhermore, the fixation of COinto cyclic carbonates catalyzed by ILs(pure ILs, complex catalyst system with ILs, supported ILs, etc.) is summarized, clearly explaining the mechanism of COfixation with ILs. Finally, exploration of some recent studies about COcapture and conversion by ILs and challenges for further progress are presented and related suggestions are put forward.