Nanofiltration　(NF)　technology　has　been　widely　applied　in　the　fields　of　wastewater　treatment,　seawater　desalination,　as　well　as　separation　and　purification　in　industry　because　of　its　high　separation　efficiency,　low　operating　pressure,　and　environmental-friendly　characters.　Polyamide　(PA)　membranes　prepared　via　interfacial　polymerization　(IP)　are　the　most　commonly　used　in　nanofiltration.　However,　the　reaction　rate　of　IP　process　is　too　fast　to　control.　Thus,　it　is　still　an　urgent　issue　to　effectively　regulate　the　IP　process　to　optimize　the　selective　layer　structures　of　nanofiltration　membranes　(NFM),　which　could　further　enhance　the　perm-selectivity　of　the　NFM　to　meet　the　required　performance　from　different　applications.　This　paper　summarized　the　progress　in　optimization　of　perm-selectivity　performance　of　NFM　including　novel　PA　NFM,　PA/nanomaterials　mixed　matrix　membranes　and　ultrathin　PA　NFM　from　the　viewpoint　of　controlling　monomers　diffusion　during　IP　process.　Then,　the　structure　tuning　methods　on　selective　layers　to　improve　the　perm-selectivity　performance　of　NFM　was　discussed.　Furthermore,　the　challenges　in　large-scale　preparation　of　PA-based　NFM　with　good　stability　and　controllability　were　pointed　out.　Finally,　the　perspectives　on　the　promising　methods　for　tuning　microstructures　and　polymerization　process　of　NFM　were　provided.　©　2020,　Chemical　Industry　Press.　All　right　reserved.