The present invention relates to a camptothecin derivative having a structure as represented by Formula (II), in which Xn+ is selected from H+, K+, Na+, Li+, Mg2+, Ca2+, Zn2+, Fe3+, and ammonium ion, while R1, R2, R3, and R4 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 C3-C6 cycloalkyl group alternatively, R1 and R2 are connected via one to three other atoms to form a heterocyclic ring and in another embodiment, R3 and R4 are oxygen atoms and connected via —O—(CH2)n—O—, forming a ring, in which n=I or 2. The compound has great water-solubility, chemical stability, and great efficacy in treatment on cancer.
