The invention provides a bilobalide B derivative having the structural formula described in the specification, wherein when R2 represents -COOH, R1 represents -X-, X represents C1-C18 alkylidene, the alkylidene is unsubstituted or substituted by C1-C5 straight chain or branch chain alkane. When R2 represents -NR3R4, R1 represents -XCO-, X represents C1-C5 alkylidene, the alkylidene is unsubstituted or substituted by C1-C5 straight chain or branch chain alkane, R3 and R4 are identical or different, and both are H, C1-C8 alkyl or C3-C10 cycloalkyl. |