Abstract: Apoptosis is a controlled program of cell death. So far, several studies have shown that small molecule apoptosis imaging tracers can help clinicians in early diagnosis of diseases, detection of disease development, early assessment of the efficacy of treatment and development of new treatment options. However, there is no ideal tracer of small molecule apoptosis imaging at present, the desirable small-molecule apoptosis imaging PET tracer should have the following characteristics:high specificity and sensitivity in detection of apoptotic cells, favorable biodistribution and safe profiles in vivo, compatible with radioactive markers and normal imaging of clinical PET. For different targets during apoptosis, currently, small molecule apoptosis imaging PET tracers are mainly divided into three categories:PET probes for caspase activation, PET probes for detection of collapse of mitochondrial membrane potential and PET probes for detection of apoptotic membrane imprint.