Abstract: Droplet size, weather conditions and operational parameters of sprayers also affect the spray coverage, absorption attachment to the target. Unmanned aerial vehicles（UAVs） currently, is considered a modern spraying technology which is helpful for efficient spraying. However, the effect of operational parameters on deposition intarget and off-target zones still required to determine. Field tests were conducted to determine spray deposition, the number of spray deposits, coverage and droplet size under various flight heights（2 and 3 m） and flight speed（2 and 3 m/s） for control of outer field control. Deposit Scan software was applied to determine the spray deposition, number of deposits, coverage and droplet diameter. The results showed that the average deposition（2.29 μL/cm~2） in the target area was found the highest when the UAV operates with 2 m/s forward speed at 2 m height（T₁）, the spray coverage under the T₁ treatment achieved 36.19% at zero position of the central flight line.At the flight central line, the relative span was 0.70, 1.01, 1.03 and 1.05 for treatments T₁, T₂, T₃ and T₄ respectively. The treatment T₁ showed maximum VMD=D_v0.5 as 448.75 μm whereas T₄ showed minimum D_v0.5with a value of 238.95 μm. The deposition in the off-target zone was nearly negligible for single-rotor UAV. This study provides a recommendation UAV operators, farmers and manufacturers for better utilization of this modern technology for weed control.