Provided are: acrylic fibers having 2-7% boiling water shrinkage and formed by the side-by-side conjugation of a copolymer A, which contains 5-10 mass % of an unsaturated monomer that can form a copolymer with acrylonitrile units, and a copolymer B, which contains 2-5 mass % of unsaturated monomer units that can form a copolymer with acrylonitrile units and 0.2-1.5 mass % of sulfonic acid group-containing monomer units; a method for manufacturing said fibers; a spun yarn containing said fibers; and a knitted fabric obtained from said spun yarn. The single fiber fineness of the heat-treated acrylic fibers is 1.7-6.6 dtex, the bulkiness is at least 380 cm3/g, the percentage of crimp is at least 15%, and the product (DKSDKE) of the knot strength (cN/dtex) and the knot elongation (%) is 10-25. The acrylic fibers have excellent crimp characteristics and anti-pilling properties.
