Background and Originality Content Catenanes are compounds composed of two or more mechanical interlocked macrocycles.[1-3] By introducing the catenanes structures into polymers, polycatenanes with chain-like mechanically interlocked structures can be obtained.[4] Since catenanes are highly free and mobile, polycatenanes possess greater flexibility and strength caused by different chain conformations compared to conventional polymers.[5-8] The categories of polycatenanes could be divided into a number of subclasses as follow,[9-15] depending on the location and connection of the catenane subunits: main-chain polycatenanes obtained by introducing difunctionalized catenanes into the linear polymer main chains or by interlocking a plurality of rings two by two; side-chain polycatenanes obtained by introducing monofunctional catenanes into the linear polymer side chains;polycatenanes based on cyclic polymers formed by two large or one large ring hanging with small rings; Unlike the above types of polycatenanes, polycatenane networks are composed of multiple interlocked rings or of catenanes and polymers, showing solid-like properties different from most of the liquid polycatenanes. Liquid polycatenanes are mostly used for theoretical research and are difficult to be widely used as macroscopic solid materials. Through the linear crosslinking, polycatenanes could be converted from liquid to gels and thus be widely used.[16] The above-mentioned polycatenanes networks formed by multiple interlocked rings are also a kind of crosslinked networks, while their structures are complex making it difficult to recognize the exact structure.[12] In recent years, many kinds of poly[2]catenane networks have been developed. For example, As shown in Scheme 1a, Huang, Wu and coworkers prepared a poly[2]catenane gel by the “click” reaction between bisvinyl [2]catenanes and poly(ethylene glycol) derivatives containing thiol groups.[17] Rowan and coworkers designed a series of poly[2]catenane gels with different numbers of interlocked units by using doubly threaded pseudo[3]rotaxane crosslinkers and covalent crosslinkers (Scheme 1b).[18] Besides, Wang, Chen and coworkers designed a poly[2]catenane hydrogel prepared by Tetra-PEG chains crosslinked by the recognition of metal ions, which was a reversible coordination interlock structure (Scheme 1c).[19] It could be found from the above-reported examples, the gel formation all relies on the polymer as part of the backbone structure. Herein, we prepared a new type of poly[2]catenane gel by entire sequential assembly of small molecules without any polymer structures. Poly[2]catenane gels were prepared based on the monomer M1 , monomer M2 (2,6-pyridinedicarbaldehyde) used for ring closing reactions and the crosslinker monomer M3 , all of which were small molecules. First, M1 of alkyl chain linking with two isophthaloyl bis(diamine) groups, self-assembled to form linear supramolecular polymers (SPs) through synergistic intramolecular hydrogen bonding and π-π interactions at higher concentrations in chloroform. When M2 and M3 were simultaneously added to the M1 solution, the aldehyde groups of M2 could spontaneously react with the amino groups of M1 to form dynamic covalent bonds (imine bonds), and ring closing behaviors occurred. The ring-closing behaviors was caused from: since the number of reactive sites of M3 was twice as many as that of M2 , the amnio groups in supramolecular polymer chains could react with M3 to form the closed ring. Additionally, M3 acted as the crosslinker to crosslink linear SPs. Therefore, the simultaneous addition ofM2 and M3 could transform linear SPs into poly[2]catenane gels. The reaction process of forming imine bonds is spontaneous and stable, and thus, it would not affect the existing non-covalent bonds and disturb the SPs formed by self-assembly.Scheme 1 Schematic representation of the three types of poly[2]catenane gels: (a) gels formed by cross-linking of catenane modified in the side chains of polymers, (b) gels formed by polymers acting as irregular catenane macrocycles, (c) gels formed by polymers acting as regular catenane macrocycles, (d) gels formed by the self-assembly of small molecules (M1 , M2 , M3 ) through non-covalent and dynamic covalent bonds