In this research work an attempt has been analysed the mechanical performance of a developed machine which can be used to remove the sugar beet leaves in the reclaimed lands before mechanical harvesting operation. The study was carried out in Port-Said Research Station, Port-Said Governorate, during April 2013. Three different speeds of PTO 540, 725 and 1000 rpm, three various forward speeds 0.48, 1.0 and 1.68 m/sec. and three different levels of cutting 3, 6 and 10 cm were conducted to evaluate the machine and assess its mechanical efficiency. Development of this machine aims to avoid spoiling roots during mechanical harvesting. Primary study was carried out to estimate the lost part during traditional topping operation, which shows that the percentage of loss in the weight reached on average 6.2%. The obtained data indicated that PTO speed of 1000 rpm, forward speed of 0.48 m/s and cutting level of 10 cm is the best treatments, which increased the topping efficiency up to 88%.