Meld experiments were carried out at Sakha Agricultural Research Station, Kafr El-Sheikh Governorate, in 1993/94 and 1994/95 seasons to study the effect of B, Zn, Mn and their mixtures on juice quality and chemical composition of sugar beet var. Ras Poly. Each of the four experiments induded 9 treatments which were the combination of 3 micro nutrient levels and three dates of application zero, 0.5 and 1.0 kg Wed; zero, 3 and 6 kg Zn/fed; zero, 20 and 40 g Mn/fed. Dates of application with all micronutrients were at sowing, 90 days and 105 days. Micro elements were applied only once as soil application. The experiments were laid out in complete randomized block design with four replications. The results of the combined analysis of the study could be summarized as follows: Boron application at 0.5 kg/fed reduced T55% at harvest, whereas Zn, Mn and the mixture showed no significant effect on TSS%. All micronutrients had no significant effect on sucrose% at harvest. Mn application at 40 g/fed significantly raised purity% at harvest. Late application of all micronutrients mixture favourably affected purity% at harvest compared with early application. The results indicated a significant increase in N% in leaves due to application of a mixture containing 0.5 kg B + 3 kg Zn + 20 g Mn/fed compared with the check treatments and the highest level as well. Significant effect was observed for application date of Mn where application at 90 days from sowing or at sowing significantly surpassed the later application at 105 days age in affecting N% in roots. The only significant effect was for Zn when it was applied at the higher level. This effect was also recorded in K% in sugar beet leaves. The interaction between levels and dates of applying micronutrients mixture had significant effect on Zn content in sugar beet root. Neither level of all micro nutrients nor application date had significant effect on B, Zn and Mn in sugar beet leaves and roots at harvest.