Because of their unique optical,electrical,and magnetic properties,fabrication of novel phthalocyanines supramolecular assemblies is becoming extremely important.However,developing phthalocyanines assemblieswith tunable supramolecular chirality is still difficult due to the good planarity of phthalocyanine molecules,which could induce strong π-π interaction and tight aggregation.Herein,the supramolecular chirality of interfacial assembly of achiral phthalocyanine was thoroughly regulated by simply using different alkali metal ions.Achiral phthalocyanine with crown ether substituents(H2Pc(15C5)4)could form chiral assemblies with helical nanostructures upon interaction with potassium ions at the air-water interface.It is found that the formation of phthalocyanine dimers plays very important role.However,smaller lithium ions cannot induce this achiral phthalocyanine form chiral assemblies.Although sodium ions can form good host-guest complex with crown ether substituents,only weak optical activity can be detected from H2Pc(15C5)4/Na+assemblies.