An improved solvent-free microwave extraction(ISFME) was used for the extraction of essential oil from dried Cinnamomum cassia Presl. Two kinds of solid microwave absorption media[carbonyl iron powder(C/P) and graphite powder(GP)] were used. When ISFME was applied, the heating rate was enhanced and the extraction time was obviously shorter than that consumed in conventional solvent-free microwave extraction(CSFME). Twenty-eight kinds of compounds in the essential oil were identified, and the total content fractions of the compounds obtained by CIP-ISFME, GP-ISFME, CSFME, and hydrodistillation(HD) were 96.65%, 96.06%, 97.22%, and 96.29%, respectively.The compounds in the essential oil obtained from Cinnamomum cassia Presl. by ISFME, CSFME, and HD were compared and the quantity of the essential oil was almost the same. The ISFME has been proved to be a feasible way to extract essential oil from dried samples, and there are several obvious advantages in ISFME over those of liD and CSFME, for example, shorter extraction time(30 min) and lower energy consumption.