Objective To find the mechanism for excitation-contraction (E-C) coupling modes in embryonic cardiomyocytes; Method The membrane potential and intracellular Calcium were respectively measured with whole cell patch clamp and Calcium imaging methods; Results There exist two kinds of E-C coupling modes. One is similar to the E-C coupling mode of mature cardio-myocytes and its membrane potential was related to Sodium Channel and L-Calcium channel. The other mode is more basic for embryonic cardio-myocytes, which is controlled by intracellular Calcium oscillationto cause the slight change of membrane potential through Na(superscript +)-Ca(superscript 2+) exchanger. Compared to the second one, the first mode is more regular. Conclusion Two kinds of E-C coupling modes exist for embryonic cardiomyocytes.