The present study aimed to determine the direct effect of araloside C on Ca2+ transient and contractions in isolated rat cardiomyocytes. In isolated adult rat cardiomyocytes, contractile and intracellular Ca2+ properties were determined simultaneously in real time by using an IonOptix MyoCam system. Western blot analysis was performed to evaluate the expressions of Ca2+ cycling proteins, including sarcoplasmic reticulum calcium ATPase 2a (SERCA2a), phospholamban (PLB), and Na+‐Ca2+ exchanger (NCX). Our results showed that araloside C directly increased sarcomere shortening, maximal velocity of shortening/relengthening (±dL/dt) and amplitude of [Ca2+]i transients in a concentration‐dependent manner. SERCA activity was also increased by araloside C. The expression of SERCA2a was not significantly upregulated, whereas PLB and NCX expressions were downregulated. These findings revealed the positive inotropic effect of araloside C on isolated rat cardiomyocytes. This effect was possibly associated with an increase in amplitude of the [Ca2+]i transient.Grant Funding Source: This study was supported by the National Natural Sciences Foundation of China (Grant No. 81173589).