The Hydraulic Bucking Unit is important equipment for make-up/break-out, repairing all kinds of tools such as drill tools, pipe stems and downhole tools for petroleum and geological prospecting industries. CZJ-I Hydraulic Bucking Unit is designed and manufactured on the basis of the advanced technology from similar equipment abroad and the actual situation of the petroleum industry in China. In view of design construction, we obtained the pieces of state patented protection right, the state certificate for new product, high- tech. certificate of provincial grade; also, we got many scientific technology awards for state and provincial grade. It owns some advantages such as high automatic function, big make-up/break-out torque, wide pipe diameter range, no sliding when make-up/break-out. Meanwhile, it also has good function for quick make-up/break-out, axial pulling. The bucking unit has got good reputation from customers domestic and abroad and well exported to many courtiers and regions.