SNCA gene is located in a quantitative trait locus for alcohol preference. Alpha-synuclein coded by SNCA gene can regulate the function of dopamine in multiple levels, and dopamine is an important neurotransmitter in alcohol preference. Variation has been found in SNCA gene carried by alcohol-dependent patients. Meanwhile, significant increase of SNCA gene expression also occurs in alcohol-dependent patients, which is closely associated with the level of alcohol dependence. Therefore, SNCA gene is believed to contribute to genetic mechanism of alcohol dependence. Here, the relationship between SNCA gene and dopamine, the variation and expression of SNCA gene in alcohol-dependent patients were reviewed.