Objective:To study the protective effect of the extracts from Sini Tang Serial Decoctions （ESTSD）against hypoxia/reoxygenation（H/R） injury on neonatal rat cardiomyocytes.Methods:Cultured neonatal rat cardiomyocytes were preconditioned with ESTSD in different concentrations（1

5

25 μg/mL）respectively.Then after H/R treatment the enzymatic activity of intracellular mitochondria dehydrogenase and the contents of intracellular maleic dialdehyde（MDA）as well as the activity of extracellular lactate dehydrogenase（LDH）were measured using colorimetric method.Results:Compared with the control group

the ESTSD including extracts from Aconite root

Dried ginger and Fistular onion stalk（EAGO）

extracts from Aconite root

Dried ginger and Prepared licorice root（EAGL）

extracts from Aconite root

Dried ginger and pig’s Bile（EAGB）and extracts from Aconite root

Dried ginger and Ginseng（EAGG）could increase significantly the activities of intracellular mitochondria dehydrogenase and had no significant difference compared with extracts from Aconite root and Dried ginger （EAG）.EAGO

EAGL

EAGB

EAGG all could significantly decrease the activities of extracellular LDH compared with the group and EAG.EAGL and EAGG decreased significantly the contents of intracellular MDA compared with the control group and EAG.Conclusion:The results showed ESTSD increased significantly the activities of intracellular mitochondria dehydrogenase

but decreased significantly the activities of extracellular LDH.EAGL and EAGG decreased significantly the contents of intracellular MDA.ESTSD has a protective effect against H/R injury on cultured neonaltal rat cardiomyocytes.