Abstract: Myocardial fibrosis is an important pathological feature of most cardiovascular diseases that progress to the end stage, and is also a key target for clinical diagnosis, risk stratification and treatment of patients with cardiovascular diseases. Therefore, early detection of myocardial fibrosis is very important for individualized treatment strategy decision-making and finally to improve patient outcome. Radionuclide-labeled fibroblast activation protein inhibitors (FAPI) selectively bind to fibroblast activation protein, enabling noninvasive in vivo visualization of cardiac fibroblast activation and assessment of myocardial profibrotic activity. This molecular imaging approach holds significant potential in cardiovascular diseases. The authors reviewed the current research status, clinical application prospects and prospects of FAPI in cardiovascular diseases.