Abstract：【Objective】To investigate the genetic polymorphisms of the CYP2C19 gene in the elderly Chinese Han populations of Guangzhou，and compare the frequencies of CYP2C19 gene polymorphisms in different populations，in order to provide accurate data for the appropriate prescription.【Methods】To detect the genetic polymorphisms of the CYP2C19 gene by the DNA microarray，and compare the frequencies of CYP2C19 gene polymorphisms in Chinese Han populations from different areas and the different races. 【Results】There were 2312 case samples in our study. The allele frequencies of CYP2C19*1，CYP2C19*2 and CYP2C19*3 were 64.27%，30.75%，and 4.98%，respectively. As the genotype，EM（*1 /*1）was 41.44%（n = 958），IM（*1 /*2，*1 /*3）was 45.67% （n = 1056），and PM（*2 /*2，*2 /*3 and *3 /*3）was 12.89%（n = 298）. The ratios of EM and IM in Chinese Han populations from different areas and all the subtypes of the CYP2C19 genotype in different minority were statistically significant. As the races，there were difference in all the subtypes of the CYP2C19 genotype when Asian populations were compared with white races（P < 1304.64）and black races（P < 0.01），which was also statistically significant.【Conclusions】The distributions of the CYP2C19 gene polymorphisms were significantly different in Chinese han populations and in different races，and the main subtypes of the CYP2C19 genotype in the elderly of Chinese han populations were IM and EM，which is beneficial for prescribing appropriate in the elderly populations.