This study investigates the distribution of ALDH2 allelic and genotypic frequencies in patients with angina pectoris across northern (Luoyang, Henan), eastern (Jiaxing, Zhejiang), and southern (Guilin, Guangxi) China, and explores the relationship between ALDH2 genotypes and selected clinical characteristics. The gene discussed is ALDH2; the disease is angina pectoris.