The present invention relates to a camptothecin derivative having a structure as represented by Formula (II), in which X n+ is selected from H + , K + , Na + , Li + , Mg 2+ , Ca 2+ , Zn 2+ , Fe 3+ , and ammonium ion, while R 1 , R 2 , R 3 , and R 4 independently represent a hydrogen, a hydroxyl group, a nitro group, a cyano group, a halogen, a carboxyl group, an optionally substituted amino group, a silicon-containing group, a monocyclic aryloxy group, an optionally substituted C1-C6 alkoxy group, an optionally substituted C1-C6 alkylcarbonyl group, an optionally substituted C1-C6 alkyl group, or an optionally substituted C1-C6 cycloalkyl group； alternatively, R 1 and R 2 are connected via one to three other atoms to form a heterocyclic ring； and in another embodiment, R 3 and R 4 are oxygen atoms and connected via -O-(CH 2 ) n -O-, forming a ring, in which n = 1 or 2. The compound has great water-solubility, chemical stability, and great efficacy in treatment on cancer.
