the caatinga biome is a source of hundreds aromatic plants with medicinal, food and cosmetics potential applications. one of them is croton sonderianus which essential oil chemical composition and yielding were studied in function of season of harvesting, pre-treatment temperature and time of extraction. in average, after gas chromatography analysis, the four major components were spathulenol (40%), 1,8-cineole (25%), -pinene (8%) and caryophyllene oxide (6%), but such percentage varied greatly in function of the three parameters studied. sample submitted to drying pre-treatment at 40^0c and 2 hours of extraction time resulted in the highest yielding. components such as spathulenol decreased near 20% from the dry to rainy season, while for germacrene d its amounts increased in the period. such results will give support for c. sonderianus management in the field cultivation and essential oil exploration.