Dynamic responses of A549 cells to epirubicin (EPI), daunorubicin (DNR), cisplatin (DDP) and carboplatin (CBP) were monitored by real-time cell electronic sensing (RT-CES) system. A new defined parameter, the detachment duration, was defined to quantitatively characterize drug-cell action mechanism. For DNR, there were two different linear dependent regions of the detachment duration. The rate constant of DNR in lower concentration region (20.4±2.0 h/μM) is much larger than that in higher concentration region (3.2±0.1 h/μM). Moreover, the rate constant of DNR in lower concentration region is close to that of EPI in higher concentration region (17.5±0.5 h/μM). Similar observation occurred in the case of DDP and CBP treatment, and the rate constant is (2.8±0.4)×10 h/μM and (4.6±1.3)×10 h/μM respectively. Taken together, A549 cells are more sensitive to DNR than EPI and to DDP than CBP. This study provides new insight into cell-drug interaction. RT-CES system may play important role in future drug screening, mechanism exploration and clinical therapy.