To provide a method of manufacturing a paper core having high strength at an end thereof without generating deformation when carrying and fitting and removing it to/from a spindle and capable of maintaining the initial length and the inner and the outer diameters for a long time.

This paper core manufacturing method contains a cylindrical member manufacturing process for manufacturing a cylindrical member 1 formed of a main body 1b having the predetermined thickness and a thin part 1a provided in at least one end of the main body 1b so that the outer surface thereof is continued to the outer surface of the main body 1b and having a thickness thinner than that of the main body 1b, and an adhesive agent coating process for coating the inner surface of the thin part 1a with the adhesive agent to form an adhesive agent layer 2, and a folding process for folding the thin part 1a. The thin part 1a is folded several times to form a spiral part 1c, and the spiral part 1c is brought in contact with the main body end surface 1f, and the inner surface of the thin part 1a at a main body side part thereof is coated with the adhesive agent by the only predetermined length to prevent the generation of overlap of the adhesive agent layer 2 when forming the spiral part 1c.