To provide a reduction gear for driving rolls, which is lighter in weight than a conventional one and which provides driving force suitable to drive a rolling mill without using a large-sized kammwalze gear.

The reduction gear 10 has one input shaft 11, and first and second output shafts 12, 13 which are different in the rotational direction each other and drives two upper and lower rolls 14, 15 which are respectively connected with the first and second output shafts 12, 13. In the reduction gear 10, the driving force from the input shaft 11 is divided in two in the axial direction by arranging first and second pinions 16, 17 on the input shaft 11, rotational driving force divided in two of the first pinion 16 is transmitted to a first output gear 18 which is installed on the first output shaft 12 through even number of intermediate gears and the rotational driving force of the second pinion 17 is transmitted to a second output gear 20 which is installed on the second output shaft 13 through odd number of intermediate gears 19.