This investigation was carried out at Plant Production Department, Faculty of Agriculture (Saba Basha), Alexandria University, Egypt, during 2014/2015 season to study the impact of reciprocal position of the conventional roller gin stand fixed knife and seed cotton grade on ginning efficiency and cotton fiber properties of two long staple cotton cultivars. Two fixed knife positions, (Reciprocal and normal position) besides, three seed cotton grades; namely; Good + ¼, Good (G), and Good – ¼, belonging to two commercial Egyptian long staple cotton varieties; namely; Giza 92 and Giza 86. The obtained results clarified that the reciprocal position of the fixed knife, surpassed the normal position and gave the highest mean values of gin stand capacity (kg/inch/hr) and lint cotton grade. Concerning H.V.I. fiber properties, insignificant impact due to the fixed knife position on the most of fiber properties was found. With respect to the effect of seed cotton grade, the highest mean values of the gin stand capacity (kg/inch/hr), ginning out-turn (%), lint grade, upper half mean length (mm), uniformity ratio, fiber strength (g/tex), fiber maturity (%) and reflectance degree (Rd %) were recorded for the highest seed cotton grade (Good + ¼). Meanwhile, the highest mean values of yellowness degree (+b), trash area (%), trash count and nep count were recorded by the lowest seed cotton grade (Good - ¼).