Experiments were carried out to manufacturing a combine prototype from the local materials to suit separating the seeds of watermelon pulp, cleaning and collecting the seeds. The experiments were carried out to evaluate the performance of a combine prototype, as well. The performance of the manufactured prototype was studied under the following parameters: four feeding rate (100,130,160 and 200kg/min), four drum speed (6.2,8.5,10.6 and 13.2 m/s) and four number of resting days after harvest (2,4,6 and 8 days) on the seed losses %, seed damaged %, productivity kg/h, machine efficiency%, consumed power kW, and operating cost L.E/fed. The experimental results reveal that the highest value of the seed losses, was 7.0% at feeding rate of 200 kg/min, drum speed of 6.2 m/s and 2 days after harvesting. While the lowest value of the seed losses, was 1.2% at feeding rate of 100 kg/min, drum speed of 13.2 m/s and 6 days after harvesting. The machine productivity increased by the increasing feeding rate and drum speed. The minimum operating cost of 185.0 L.E./fed., was recorded at feeding rate of 100 kg/min,drum speed of 13.2 m/se and 6 days after harvest.