CDKI-83 is a potent CDK9 inhibitor. The compound shows effective anti-proliferative activity in human tumour cell lines with GI50 <1 μM, and is capable of inducing apoptosis in A2780 human ovarian cancer cells as determined by the activated caspase-3, Annexin V/PI double staining and accumulated cells at the sub-G1 phase of cellcycle. The research results suggest that combined inhibition of CDK9 and CDK1 may result in the effective induction of apoptosis and CDKI-83 has the potential to be developed as an anti-cancer agent.