Objective: Structure and ultrastructure of cultural materials were studied to explore the correlation between the structure and the accumulation of oridonin. Method: High performance liquid chromatography was used to determine the changes of oridonin in vitro Rabdosia rubescens. On the basis of it

the anatomy of cultural materials of R. rubescens were compared using light microscopy

and transmission electron microscopy. Result: The content of oridonin was higher in donor plant (leaf) tissues

but as they began to dedifferentiation into callus

oridonin were absent in the dedifferentiation callus

when the calli initiated organogenesis (bud primordial)

it started appearing. As the leaf dedifferentiated into callus the number of chloroplast decreased. At the same time

the content of oridonin was decline until absent. But when the oridonin accumulated

the number of chloroplast increased again and the differentiation of vascular was founded in the cultural materials. Conclusion: The result showed that the number of chloroplast and differentiation of vascular played key role in biosynthetic pathway of oridonin.