Infrared　nonlinear　optical　(IR-NLO)　crystals　have　attracted　many　attentions　due　to　the　frequency-conversion　capability　to　generate　coherent　tunable　IR　laser　output　for　military　and　civil　applications.　Chalcogenides　as　a　most　popular　branch　of　IR-NLO　materials　are　the　competitive　candidates　owing　to　their　large　second-harmonic　generation　(SHG)　coefficient　(deff)　and　broad　transmission　regions.　Currently,　how　to　obtain　the　non-centrosymmetric　(NCS)　structure　and　realize　the　coexistence　of　wide　energy　gap　(Eg　&　GE;　3.0　eV),　sufficient　deff　(&　GE;　1.0　x　AgGaS2),　and　beneficial　phase-matching　(PM)　feature　are　the　two　major　challenges　faced　in　this　field.　The　former　can　be　effectively　solved　through　the　combination　of　local　asymmetric　units　and　chemical　substi-tution　strategy,　while　for　the　latter,　there　is　no　systematic　survey　and　lack　of　universally　applicable　methodology.　In　this　review,　40　IR-NLO　chalcogendides　are　selected　based　on　the　aforementioned　two　challenges　and　divided　into　7　types　according　to　the　different　chemical　components.　The　composition-structure-performance　relation-ships　and　the　theoretical　origin　of　their　IR-NLO　properties　are　summarized　systematically.　At　length,　some　useful　information　and　development　prospects　were　briefly　discussed,　which　may　offer　new　ideas　and　promote　the　discovery　of　IR-NLO　materials　with　the　ideal　comprehensive　performance.