One of the methods for increasing yield per hectare is to change the row width from 60 cm to 50 cm. For using medium-power tractors (JD 3140) available in Iran for pulling a three-row sugarbeet lifter in 50-cm row width crop, vibrating the shanks of the sugarbeet lifter was recommended. Effects of vibration frequency and approach angle of a vibratory sugarbeet lifter on its performance during harvesting were studied. Draft resistance, slippage, percent of broken and non-harvested tubers were determined for four vibration frequencies (0, 9, 10 and 12 Hz) and three approach angles (11, 24 and 36 deg.) using a factorial treatment arrangement in a complete randomized block design with three replications. The results of analysis of variance indicated that all measured parameters were significantly affected by the frequency of vibration and the approach angle of the lifting shares (P 0.01). The results showed that variations in draft and slip were similar with frequency and approach angles. The maximum draft value was at 36 deg. of approach angle and zero frequency (non-vibrated shanks) with 12.1 kN, while corresponding minimum value was at 24 deg. of approach angle and zero frequency with 7.7 kN. Optimum slip values (10-15 percent) were obtained at approach angles and frequencies of 11 deg. and 12 Hz, 24 deg. and 10 Hz and 36 deg. and 12 Hz, respectively. Minimum percentages of broken and non-harvested tubers were obtained at approach angle of 24 deg. and frequency of 9 Hz (1.4 and 5.1 percent, respectively). The results indicated that percent of non-harvested tubers decreased with an increase in approach angle. However, percent of broken tubers decreased and increased with an increase in approach angle and vibration frequency, respectively. A ratio (K) of draft resistance and percent of harvested beets (undefected and broken tubers) was definded for selection the optimum combination of approach angle and vibration frequency. The analysis of variance showed that K ratio was significantly affected by frequency and approach angle and their interactions (P 0.01). Based on K ratio, optimum operating conditions for sugarbeet harvesting with the vibratory lifter is at approach angle of 24 deg. and vibration frequency of 10 Hz.