Abstract: Objective To compare the content of toxical substances and the acute toxicity of Rhizoma Pinelliae in different processing, and evaluate the processing's influences on the content of toxical substances and acute toxicity. Methods UV method, HPLC method, acid -base titration and the classical method of acute toxicity were used to determine the content of toxical substances and compare the acute toxicity of Rhizoma Pinelliae in different processing. Results The content of total organic acid is: 75% alcohol-infiltration>75% alcohol-extraction>30%alcohol-extraction> 30% alcohol -infiltration >water -infiltration抑water -extraction; the content of total alkaloid is: 75% alcohol -infiltration> 75% alcohol -extraction >30% alcohol -infiltration >30% alcohol -extraction >water -infiltration抑water -extraction. MTD value can betested in 75% alcohol -infiltration and 75% alcohol -extraction groups, while MLD value can be tested in other groups. The comparation of acute toxicity is: 75% alcohol-infiltration>75% alcohol-extraction>30% alcohol-infiltration>30% alcohol-extraction >water-infiltration >water -extraction. Conclusion Extraction has certain influence on the content of toxical substances and acute toxicity of , and the toxicity of Rhizoma Pinelliae has some relevance with the content of total organic acid and total alkaloid.

Key words: Rhizoma Pinelliae , extraction, toxical substances, acute toxicity