The essential oil of Citrus microcarpa peels was applied in many fields, and the methods to improve the efficiency of citrus exploitation were increasingly concerned. In this study, citrus essential oil was extracted from calamondin by hydrodistillation. This study was carried out to investigate the factors affecting the distillation of essential oils. The highest performance of the distillation process was 2.45 % with optimal conditions (material-water ratio of 1:3 g/mL, time of 2 h, the temperature of 120 ºC). Moreover, calamondin (Citrus microcarpa) peels oil extract was analyzed by gas chromatography-mass spectrometry (GC-MS). The primary compound of calamondin essential oil include limonene 96.925 %, β-myrcene 1.424 %, 1R-α-pinene 0.561 %, cyclohexene 0.343 %, 1R-α-pinene 0.561 % and β-cubebene 0.598 %