This research was basically carried out to modify the longitudinal axial flow rotor for threshing wheat machine to suit threshing rice crop. Three phases were done to improve and modified this machine. Firstly, adding four rasp bars on the front part of threshing zone. Secondly, replacing four straight paddles by rasp bars on the front of separating sector of rotor and finally, alternating the stable clearance zone threshing of rotor by another inclined one. Harvester forward speeds of 1.5, 1.7 and 2.0 km/h; peripheral rotor speeds of 17.0, 19.5 and 21.5 m/s; inclined concave clearances of 7:4, 6:4, 5:4 and 4:4cm under moisture contents of (32/24), (27/21) and (20/16) for (straw/grain%, d.b.) were evaluated. Number of jamming times per feddan, threshing efficiency, visible grain damage, field efficiency and power requirement were estimated. In conclusion, higher efficiency attained when threshing was done at lower moisture content and higher rotor speed. After modification, field efficiency increased to 80% under forward speed of 2.0km/h with rotor speed of 21.5m/sec, threshing efficiency reached to 98% with grain damage of 1.5% while power requirements decreased to 47.35 kW.