Objective This study focused on the effect of passive cigarette smoking on heart and circulating cardiac biomarkers in rats.Methods 20 male SD rats were randomly divided into passive cigarette smoking group and control group. The passive smoking group was exposed to cigarette smoke for a period of 84 days while the control group was exposed to normal air. Echocardiography was used to evaluate cardiac function in the 8th week and 12th week. After the last examination, the rats were killed and the secrum was removed to test the cardiac biomarkers and the ventricular tissue for biochemical histopathological studies.Result Passive cigarette smoking rats had larger diastolic and systolic left ventricular diameters adjusted for body weight, as well as LVIDd. After a period of passive smoking, the LVIDd became larger, Meanwhile, the circulating cardiac biomarkers were higher. The ventricular tissues removed from the passive smoking rats showed some degree of separation between cardiac muscle fibers, and lymphocyte infiltration and blood vessel congestion were also observed.Conclusion Passive cigarette smoking impacts the cardiac structure of rats. The influence becomes obvious with the accumulation of the smoke. It may also lead to cardiac damage.