A　new　metal-organic　framework,　{[(CH3)(2)NH2][Co2NaL2(CH3COO)(2)]center　dot　xS}(n)　(BUT-51,　H2L　=　5-(pyridine-4-yl)　isophthalic　acid)　with　two　types　of　nanotubular　channels,　was　synthesized　and　used　in　dye　adsorption.　It　was　found　that　cationic　dyes,　including　Methylene　Blue　(MB),　Acridine　Red　(AR)　and　Acriflavine　Hydrochloride　(AH),　can　be　rapidly　adsorbed　by　BUT-51,　but　larger　Methylene　Violet　(MV)　and　anionic　Methyl　Orange　(MO),　as　well　as　neutral　Solvent　Yellow　2　(SY2),　can　hardly　be　adsorbed.　These　results　imply　that　the　adsorption　behaviour　of　BUT-51　with　the　cationic　dyes　follows　not　only　a　charge-but　also　size-and　shape-exclusive　effect.　Surprisingly,　BUT-51　also　preferentially　adsorbs　(or　separates)　AH　from　MB　and　AR,　respectively,　in　their　mixed　acetone　solution,　probably　due　to　the　coordination　between　AH　and　Co2+　in　its　framework.　Furthermore,　AH　uptake　can　change　the　porosity　and　framework　stability　of　BUT-51　to　give　a　robust　partner.