Paeoniflorin and paeonol are major components found in the Paeoniaceae family such as Paeonia lactiflora Pallas and Paeonia suffruticosa Andrews. Paeonia lactiflora Pallas has traditionally been used to relieve spasmodic abdominal pain as well as muscle stiffness and Paeonia suffruticosa Andrews has been used to enhance blood flow and to relieve joint pain in Korea, China and Japan. Current research has shown that paeoniflorin has protective effects in acute myocardial ischemia via improving coronary blood flow and blocking the L-type calcium channels. It has also been reported that paeonol blocked the voltage-gated sodium channels. However, there is lack of research to reveal the relationship between cardiac function and blockade of ion channels by both compounds. In this study, therefore, we aim to investigate whether paeoniflorin and paeonol have antiarrhythmic effects via modulating cardiac ion channels. We collated the effects of paeoniflorin and paeonol on multiple ion channels such as the fast sodium channel, the L-type calcium channel, and the rectifying potassium channel from published papers. To incorporate the information on multi-channel block, we computed the effects using the mathematical cardiac model of guinea-pig ventricular cell (Noble 1998 model) and induced early afterdepolarizations (EADs) to simulate what would be an arrhythmia in the whole heart. We then showed that both paeoniflorin and paeonol enabled recovery of the cardiac ventricular action potential from EADs through blocking of the cardiac L-type calcium channel and sodium channel effectively. This finding, therefore, suggests that paeoniflorin and paeonol possess antiarrhythmic activity and they and their original herbs can be potential candidates as antiarrhythmic drugs. .