The chopping mechanism of a stationary Japanese chopper has been developed at the workshop of Rice Mechanization Center. Meet El-Dyha. Kafr El-Sheikh Governorate during summer season of 2005. The modified chopping mechanism was proposed to avoid the continued vibrations as a result to extend the feeding interval and non-uniformity the distribution of dynamic load on the chopper i.e overload or no load which causes decrease the expected life time of chopper. productivity and efficiency of the machine as well as using a high levels from operating speeds to increase the chopper capacity and to improve its overall efficiency. The feeding mechanism has been modified throughout using two drums to uniform the feeding and distribute the dynamic load consequently. reduce the vibrations and increase the machine stability. The cutting system has been modified throughout fixing an electrical motor, its power 5 kw 1500 rpm on the frame to obtain four different operating speeds by using two fabricated polleys with different diameters. A moving frame by three wheels was used instead of the fixed frame to facilitate the conveying, adjusting and operation of the chopper. The field experiment were conducted at four cutting speeds of 0.75. 1.19. 1.33 and 1.81 mis as well as four feeding speeds of 0.28, 0.45. 0.75 and 1.22 mis. Two different Shapes of cutting knives (straight sided-edge shaped and serrated edge) had been used for cutting the grape residuals. The cutting efficiency, productivity, cutting length and energy consumed compared with energy of local cutting tools were been studied. The obtained results can be summarized as follows: Developing the feeding and cutting mechanisms of stationary Japanese chopper improved its performance through. increasing its productivity and efficiency as well as decreasing cutting energy and ch0pping lengths. The maximum value of machine efficiency (93.16%) and capacity (4.192 Mgih) have been accomplished with feeding mechanism and cutterhead speeds of 1.22 and 1.88 mls respectively. Using serrated-edge shaped. But. at 0.28 mls feeding mechanism speed and 1.88 mis cutterhead speed gave the highest value of cutting efficiency (93.85%). The minimum value of chopping length was 1.0 cm at feeding mechanism speed of 0.28 and 0.75 mls using cutting knives of serrated-edge shaped while. The lowest value of energy consumed was 0.776 kW.hn at 1.22 mls feeding mechanism speed and cutterhead speed of 0.?5 mrs. The optimum performance of the developed chopper was obtained at feeding mechanism speed of 0.28 mls and cutterhead speed of 1.88 mis by using cutting knives of serrated-edge shape.