NOVELTY - A carbon nanotube-containing composition contains a conductive polymer (a) having ammonium salt of sulfonic acid group and/or ammonium salt of carboxylic acid group, a solvent (b) and carbon nanotube (c). The ammonium ion of the ammonium salt is given by preset formula.    USE - For manufacture of composite and carbon nanotube-containing polymeric material for carbon nanotube-containing carbon material (all claimed) and for separator, chemical sensor, anticorrosive agent, battery and fuel cell. The composite is used for electrophotographic recording material, industrial packaging material and overhead projectors.    ADVANTAGE - The coating film of the carbon nanotube-containing composition has excellent water resistance, weather resistance, hardness, mechanical strength and electroconductivity. The carbon nanotube-containing composition has excellent film formability and moldability.    DETAILED DESCRIPTION - A carbon nanotube-containing composition contains a conductive polymer (a) having ammonium salt of sulfonic acid group and/or ammonium salt of carboxylic acid group, a solvent (b) and carbon nanotube (c). The ammonium ion of the ammonium salt is given by formula (1).    R48-R51=hydrogen, 1-24C alkyl, aryl, aralkyl, phenyl, benzyl, -R135OH, -CONH2 or -NH2, at least 1 of R48-R51 is 5C or more group;and    R135=1-24C alkylene, arylene or aralkylene.    INDEPENDENT CLAIMS are included for the following:    (1) manufacture of the carbon nanotube-containing composition, which involves mixing the conductive polymer (a), solvent (b) and carbon nanotube (c);    (2) composite which has a coating film which consists of the carbon nanotube-containing composition, on at least one surface of a base material;    (3) manufacture of the composite, which involves coating the carbon nanotube-containing composition on at least one surface of the base material, heat processing or leaving at normal temperature and forming coating film;    (4) physical property evaluation of the carbon nanotube, which involves evaluating the physical property of the coating film formed by the above method;    (5) carbon nanotube-containing polymeric material formed by removing solvent from the carbon nanotube-containing composition; and    (6) carbon nanotube-containing carbon material formed by baking the carbon nanotube-containing polymeric material.