In this paper, a method of line scan-conversion is presented by calculating the intersection point of straight line with the middle scan line of screen. With this method, the pixel’s screen coordinate of spatial line could also be obtained. Moreover, raster precision is exactly the same as that of Bresenham’s middle algorithm; and more than or at least one pixel could be obtained at a computational effort of one inner loop. However, to Bresenham’s middle algorithm, only one pixel is obtained in one inner loop’s calculating.