Abstract:Polyacrylamide gradient gel electrophoresis was adopted to test esterase isozymes of 8 species of Fritillaria. Their bulbs were collected from 19 populations in Gansu province. It is shown that there are 28 bands observed which can be divided into four zones: A, B, C and D. All taxa have A2, A7 and C22 bands in the zymograms, but they are different to some extent in the number of isozyme bands, migration rate of enzymes and their chromatogram scanning. The esteraase isozymograms can generally be repeated, and as a biochemical index are stable of taxonomic importance in Fritillaria. Based on the dissimilarity of isozymograms、 between F. taipaiensis var. zhouguensis and F. taipaiensis the authors suggest that F. taiensis var. zhouquensis is raised to the rank of species.