In order to raise utilization ratio of the essential oil and main components from isonerolidol type leaves, and determine the optimum harvesting time of leaves, dynamic change rule of the essential oil and main components contents during different months from isonerolidol type leaves were tested and analyzed. Results indicated that there were significant differences in the average of oil content in isonerolidol type leaves from different months, the variation trend of average oil yield in isonerolidol type leaves was gradually ascending from March to September, then gradually declining till the next growth period of January. Therefore, September was the best harvesting time for the oil; However, the contents of isonerolidol, 1,8–cineole, α–terpineol, methyl eugenol, methyl isoeugenol,sabinen, and 3–methyl–2– butenoicacid cyclobutyl ester in the oil of isonerolidol type leaves were significant difference between the different months, except for spatulenol and caryophyllene. The best harvesting time for isonerolidol, 3–Methyl–2– Butenoicacid, cyclobutyl ester, 1,8–cineole, methyl isoeugenol, α–terpineol, methyl eugenol and sabinen was from May to July, in November, in January, in March, in May, in January and March, respectively.