In order to raise the processing efficiency and quality of the larger workpieces, an innovative line scanning selective laser sintering rapid prototyping (SLS RP) process is introduced, differing entirely from the vibrating mirror spot scan. Changing the output beam of CO2 laser into a linear beam by cylindrical lenses, the length of the linear beam on the working plane can be varied from the maximum designed length to a single spot by a zooming unit during scanning. The line width 0. 13mm and variable line length range 0. 13-40mm can be achieved. Laser power and scanning speed are optimized for different line length to sinter the various organic powder materials sufficiently. The processing efficiency and quality of the innovative line scanning system is better than that of the vibrating mirror spot scan for larger workpieces，so the application region of SLS RP technology may be expanded greatly.