Mixed yarn

A mixed yarn having a uniform dyeability to an acid dye which comprises at least two kinds of polyamide filaments differing in shrinkage, characterized in that

• A. a lower shrinkage filament in which the amount of units each represented by the general formula ##SPC7##
• or the sum total of the amount of said units and the amount of other isomorphous units is at least 75 mole %, and in the carboxylic acid component in the polymer, ##SPC8##
• and in the diamine component in the polymer,
• --HN(CH.sub.2).sub.n NH-- unit .gtoreq. 70 mole % (3)
• and, (B) a higher shrinkage filament in which the amount of units each represented by the general formula ##SPC9##
• or the sum total of the amount of said units and the amount of other isomorphous units is smaller than that of said lower shrinkage filament by at least 15 mole % and at least 20 mole % of non-isomorphous units is contained, and wherein in the carboxylic acid component in the polymer, ##SPC10##
• and in the diamine component in the polymer,
• --HN(CH.sub.2).sub.n NH-- unit .gtoreq.50 mole %, (6)
• wherein the content of amino end groups in the lower shrinkage polymer is about 5 .times. 10.sup.-.sup.5 - 12 .times. 10.sup.-.sup.5 mole/g, said content in the higher shrinkage polymer is about 3 .times. 10.sup.-.sup.5 - 10 .times. 10.sup.-.sup.5 mole/g and the content of amino end group in the lower shrinkage filament is larger than that in the higher shrinkage filament by about 2 .times. 10.sup.-.sup.5 - 8 .times. 10.sup.-.sup.5 mole/g.