Abstract: A new camptothecin(CPT) derivative CPT-A was synthesized by modifying camptothecin, one of the most important natural products. Its chemical structure was identified using 1D and 2D nuclear magnetic resonance(NMR) techniques. Both ¹H and ¹³C chemical shifts of CPT-A were exactly assigned. The results of the identification of camptothecin skeleton are basically consistent with those reported in the literature. In this study, the number 6 carbon of camptothecin skeleton and the number 3' carbon of benzene are completely overlapped. This phenomenon is seldom seen in the ¹³C NMR spectra. NMR data support for the discovery and structural identification of natural products of camptothecin derivatives can be obtained in the study. Furthermore, a methodology was involved in the analysis of NMR spectra.