ABSTRACT
Objective To study the correlation and variation between plants of internal transcribed spacers (ITS) sequence of the six medicinal plants of Euphorbia L. in Anhui and Jiangsu Provinces, in (order) to provide their DNA molecular marker to identify and explore the phylogenetic relationship of the plants of [WTBX]Euphorbia L. Methods To determine rDNA ITS sequence for the plants of Euphorbia L. by PCR technology. Results The sequences of ITS1 in the six species ranged from 255 to 262 bp in length and those of ITS2 from 214 to 236 bp. The dendrogram was obtained with Mega2 analysis. The analysis result was consistent with those from morphology. Conclusion The method can be used to identify the plants of [WTBX](Euphorbia) L. among different species and to differentiate their fakes.