Mechanical harvesting of citrus by vibrating action depends on some parameters; frequency, amplitude and shaking time. The current study aimed to determine the optimum values of citrus performance parameters. The shaking machine was operated at three levels of frequency 2, 4 & 6 Hz, three levels of amplitude 50, 55 & 60 mm and shaking time was 10 sec. The results showed that the maximum fruit removal (FR) value, 99.1 %, was achieved at a frequency of 6 Hz and an amplitude equal to 60 mm. this same frequency and amplitude also achieved the maximum,100%, degree of ripe-fruit selectivity (DS).