The association of the variant in the 5'-regulatory region of angiotensinogen gene with primary hypertension in the Han Nationality in China was studied by applying PCR-SSCP analysis and DNA cycle sequencing. The frequencies of three identified SSCP-patterns (pattern-A, B, C) in 73 hypertensive subjects were compared with those in 74 normal controls. It was found that the number of pattern-C was higher in the study group (5/73) than in the controls (1/74). The results of DNA sequencing showed that the difference of three SSCP-patterns was caused by a nucleotide substitution G-->A at -216 locus in the 5'-upstream region of angiotensinogen gene, and the subjects with pattern-C were homozygous for mutant A-allele (genotype A/A). These results suggest that the identified gene variant may be associated with primary hypertension.