Blossom of our orange tree is used in producing perfume, but the primary application is in the shape of dry blossom especially as liquid extracts. In herbal medicine, Sour orange blossom is a relaxation agent and anti anxiety and disorder in nervous system and reduces nervous headache and migraine as well. Considering economic value of sour orange blossom, blossom has been harvested each year at a specific time. Hand harvesting of blossom requires time and increases costs and may result in tree injury. On the other hand, use of tree trunk shakers has problems because of size, weight and high power requirement. In this investigation a unique and precise logically programmable electro pneumatic limb shaker of impact type was designed and developed to mechanically harvest sour orange blossom. The hand- held shaker was pneumatically powered and driven by a rechargeable air compressor and electric motor. The shaker consisted of these parts: impact gripper, boom, pneumatic actuator, metal strap, frequency changing knob, programmable logic controller (PLC) and pneumatic valve. To reduce transfer of vibration from shaker to operator’s hand, a metal hand strap was shaped in a way that was hinged to the tree while working and at the same time transferring some of the weight of the shaker. In order to design the shaker, physical and mechanical properties of sour orange tree were investigated and vibration force for detachment of the blossom from the branch was determined. In order to determine the vibration force, vibration system of branch- shaker was presumed with one degree of freedom. The branch was presumed to be a cantilever beam and natural frequencies of beam were determined. The static force of sour orange blossom detachment was determined using universal testing machine. The developed machine had the ability to provide three levels of shaking amplitude (20, 30 and 40 mm) at oscillating frequencies of (1, 2, 3, 4, 5 and 6 hertz). By combining any of the three amplitude levels with four levels of shaking frequency, the most suitable combination to obtain maximum orange blossom removal percentage with least damage could be obtained. Harvesting rate was calculated by weighing both the harvested and unharvested orange blossom. A 3*4 factorial experiment with completely randomized block design with four replications was conducted to investigate the effects of shaking amplitude and frequency on blossom detachment. Experiments were conducted in the orchards of Dezful Jolgedez CO. in Khuzestan Province, Iran. In this experiment four levels of frequency (1, 2, 3 and 4 hertz), three levels of amplitude (20, 30 and 40 mm) were investigated. The analysis of variance and mean comparison conducted with SAS and MSTAD-C and results obtained showed that the effect of shaking frequency and amplitude and interacting effects were significant on sour orange blossom detachment. Harvesting rate of the shaker increased with