The main pathological change in Parkinson’s disease is the degenerative lesion of dopaminergic neurons in the nigrostriatal zone, resulting in a decrease of dopaminergic transmitters in the nigrostriatal pathway. The main pathological changes of PD are concentrated in the terminal synapses of dopaminergic neurons in the striatum. Feng Tao, Center of Neurology, Beijing Tiantan Hospital Specific metabolic enzymes and proteins in these endings, such as dopamine decarboxylase in presynaptic nerve endings, dopamine transporter in presynaptic membrane and type II vesicular monoamine transporter in intrasynaptic vesicle membrane, and dopamine D2 receptor in postsynaptic membrane can be regarded as diagnostic markers of Parkinson’s disease. Chemically synthesized radioligands as tracers can bind to these enzymes or proteins and then reveal changes in the presynaptic and postsynaptic dopaminergic systems with the help of nuclear medicine imaging techniques (PET imaging techniques). The dopamine transporter (DAT) is an important marker of presynaptic dopaminergic endings. DAT is a dopamine transporter protein located in the presynaptic membrane of dopamine neurons, and its function is to ensure the normal physiological function of the synapse by actively reuptaking dopamine released into the synaptic gap back to the presynapse. DAT-PET is considered to be the most sensitive molecular imaging marker for PD, and it can be used to differentiate PD from non-PD-like tremor, drug-induced Parkinson’s syndrome, psychogenic Parkinson’s syndrome, and vascular Parkinson’s syndrome.