OBJECTIVE: To evaluate the influence of sinusoidal vibration stimulation on the Sprague-Dawley (SD) rat heart. STUDY DESIGN: Three-month-old SD rats were randomly divided into control group (A), vibrating group (B), sham operation group (C), sham operation vibrat-ing group (D), ovariectomy (OVX) group (E) and OVX vibrating group (F). SD rats started to vibrate 1 week after the operation: one 10-minute 50-Hz sinusoidal vibration per day, except for Saturday and Sunday. In the second, eighth, and twelfth weeks after vibration stimulation, SD rats were sacrificed in batches, and their hearts were taken out to measure the wet weight and calculate heart relative wet weight. RESULTS: Through 50-Hz sinusoidal vibration, heart relative wet weight declined during the second week, and the heart relative wet weights of the vibrating group, sham operation group, and OVX group were significantly lowered; relative humidity of the heart was more sensitive than heart wet weight. CONCLUSION: Fifty-Hz sinusoidal vibration could be a new way to prevent and treat myocardial hypertrophy, and heart relative wet weight became a new index to define external cardiac stimulators. (Anal Quant Cytopathol Histpathol 2021;43:968-972) © Science Printers and Publishers, Inc. © 2021 Science Printers and Publishers Inc.. All rights reserved.