The non-uniform size of multi-germ beet seeds has made them more difficult to plant uniformly than the most grain crops. Therefore, this research was intended to design and constructed a simple grading machine for grading the sugar beet seed. The purpose of the designed grader is to sorting the beet seeds into three classes such as; (small, medium, and large seeds with high ability to germinate from medium seeds). Some physical and mechanical properties for beet seeds were measured. The obtained data helped in designing and manufacturing the proposed grading machine. The experiment was done to study the effect of seed specific load on screen, kinematic factor, screen slope, and screen to spiral speed ratio. The performance of grading machine was measured in terms of seed quality, grading capacity, grading efficiency, and energy requirements. Results showed that this machine is quite successful for grading multi-germ beet seed. The best result was obtained at 0.9 kinematic factor, 0.1 kg/m² s seed specific load, and 10 degrees screen slope. At these levels the maximum grading efficiency of 92 %, 0.157 kg/s grading capacity, and 5.2 kW.h/Mg energy requirements were obtained. Before grading process, germination percentage and coefficient of variation of multi-germ beet seed were 94.5 % and 15.5 % respectively. Meanwhile, after grading process using the designed grader machine, the seed germination and coefficient of variation were significantly improved to be 98 % and 6.4 % respectively.  Generally, results of the test, concluded that the fabricated grading machine was met the design objectives. It was believed that this grading machine was simple in design, easy in operation, and it greatly improved the uniform size and quality of multi-germ beet seeds.