PURPOSE: To improve a rocking die forging machine to control the motion of an rocking and rotating tool holder by changing gears to be engaged.

CONSTITUTION: An inner gear ring body 10 capable of being rotated around the axis which is slightly eccentric relative to the center line C of a fixed casing A as indicated by the arrow D, and capable of adjusting the position at four prescribed positions during the operation as indicated by the arrow B is provided, and a large gear 10a, a small gear 10b, two planetary gear bodies PL1, PL2 of double pinion type, and an annular gear 13 are provided. The inner gear ring body is selected at four different positions by operating a push-button to change the engaging position of inner and outer gears, and the rotational motion of the planetary gear body is changed thereby, an eccentric sleeve 10A which is directly connected to the annular gear is eccentrically rotated by this motion, and the motion is transmitted to a tool shaft 100 of rocking and rotating type through a double eccentric sleeve DES, and it is also transmitted to a work to achieve the rocking die forging.