Disclosed herein is a nozzle rotation body for a reaction-type steam turbine, the rotation body rotating by ejection of fluid from the nozzle. The rotation body includes: a disk-shaped body (210) having an shaft hole that is formed in the center thereof and coupled to a rotary shaft; a guide portion (220), projected in the vertical direction and integrally formed with the body (210) to have a guide side (GS) providing a plurality of exhaust flow paths (221) forming equal angles to each other in the helical direction around the shaft hole; a nozzle piece (230), positioned on each front end of the exhaust flow paths (221) and assembled with the body (210), to have a cross section of the same shape as the cross section of the exhaust flow paths (221) and have a narrow width section; and a fastening unit having at least one bolt (241) and at least one assembly pin (242) coupling the nozzle piece (230) and the body (210).