The aim of our study was to find out the mechanisms of cardiomyocyte contractile activity disturbances under the influence of anthracycline antibiotics and curcumin correction capabilities, to clarify the role of the mitochondrial membrane potential changes in cardiomyocyte contractile activity. It was investigated disturbances of contractile activity of the rat neonatal cardiomyocytes under the influence of anthracycline antibiotics (doxorubicin), and the possibility of correcting these violations using antioxidant curcumin. In addition, there was researched the role of mitochondrial membrane potential changes in reducing contractile activity of the cardiomyocytes. We established that doxorubicin causes significant changes in all reduction parameters compared to control: increased frequency of spontaneous contractions, violation of rhythm, lower amplitude and the shortening %, increase in the maximum speed of contraction and relaxation without changes in duration of these processes. Compatible incubation with doxorubicin and curcumin caused a consid- erable decrease of the incidence of spontaneous emission (3 times), restored their rhythm, increasing the amplitude of 2 times and the shortening % (8,15 ± 0,37), rising the maximum speed reduction to 1,8 times and the relaxation speed of 16 %, with no significant change in duration of these processes compared to monoincubation with doxorubicin. In the fluorescence study of neonatal cardiomyocytes mitochondrial potential was detected a significant reduction in mitochondria color brightness under the influence of doxorubicin - in 1,7 times compared to control. A compatible incubation of cells with curcumin and doxorubicin resulted in an elevation of mitochondria fluorescence (2,2 times compared to using of doxorubicin only).