Novel compound, extract containing same and its preparing method and use

The invention relates to Tibet jerusalemsage extract and the manufacturing method. It contains at least 20% diterpenes compound. The method includes the following steps: using over 50% alcohol to extract the effective constituent; filtering by macro-porous resin; eluting by over 40% ethanol to eliminate poisonous matter; eluting by over 80% ethanol to enrich the effective constituent which has the active for relieving cough.