A general and facile approach for highly selective separation of ionic dyes is described. Core-shell amphiphilic marcromolecular nanocapsule (CAM) derived from hyperbranched polymer is structurally featured by the dense functional groups populated in the core, which provide a unique opportunity for the core engineering and structure-property evaluation of a CAM. Here hyperbranched polyethylelimine (HPEI) is alkylated with 2-hexadecyloxymethyloxirane via a single-step, mild and efficient reaction, leading to HP(EI-CI6(x)) (x = 0.10 (1a), 0.15 (1b), 0,20 (1c), 0.30 (1d), 0.60 (1e), and 0.90 (1f), where x represents the fraction of amino protons being alkylated) with a hydrophobic shell and a hydrophilic core. The core of 1d is further treated with propylene oxide, glycidol, methyl iodide, or succinic anhydride, respectively, leading to hydroxyls (2d. 3d), quaternized ammoniums (4d) and carboxyls (5d) populated core. These CAMS show different guest loading capacity and guest recognizing ability and call be used for highly selective separation of water-soluble ionic dyes. For example, la-le can 100% separate cationic-anionic dyes and some anionic-anionic dyes; 4d shows the highest encapsulating capacity and call encapsulate a broad spectrum of guests but with a relatively low selectivity; If and 2d call recognize broader spectrum of guests and can similar to 100% separate various binary anionic dyes and sonic ternary anionic dyes. These CAMS can recognize not only anionic dyes bearing different charges but also those bearing the same number of ionic charge(s). These results indicate that for a host-guest system mainly based on nonspecific interaction, highly specific encapsulation call be a general case because accumulated multisite statistical host-guest interaction can differentiate the guests, where the core of the CAM plays a crucial role ill guest recognition,