OBJECTIVE: To compare the effects of different processing methods on the content of total flavonoids in Eucommia ulmoides so as to provide a scientific basis for reasonable processing of E. ulmoides in the production place. METHODS: Fresh E. ulmoides was made into flakes and shredded slices. The E. ulmoides with the two properties was classified on the basis of “sweating” and “without sweating” and dried in the shade, in the sun or by baking (60 ℃, 80 ℃ and 100 ℃) or dried in the sun after microwave drying (5 min, 10 min and 15 min) for the preparation of samples. With rutin as the reference substance, ultraviolet spectrophotometry was adopted to determine the contents of total flavonoids in all the samples at a wavelength of 510 nm. RESULTS: Different processing methods had effects on the content of total flavonoids in E. ulmoides. For the samples processed by the same drying method, the content of total flavonoids in those without “sweating” was higher than that in “sweating” ones (P<0.05 or P<0.01); for the samples with the same property and processed by different drying methods, the content of total flavonoids arranged from high to low were microwave drying>baking>dried in the sun>dried in the shade, where the content of total flavonoids in those dried in the sun after 10 min microwave drying was the highest; the content of total flavonoids in the shredded slices was higher than that in the flakes. CONCLUSIONS: For clinical application of the pharmacological action of total flavonoids in E. ulmoides, it is suggested that fresh E. ulmoides cut into shredded slices and without “sweating” should be selected and dried in the sun after microwave drying.