Aim To investigate the relationships between essential hypertensives and the polymorphism of angiotensin II type 1 receptor (AT1R) gene in youth. Methods 104 hypertensive and 154 normotensive subjects were studied. All subjects were divided into four groups according the age: young hypertensives, aged hypertensives, young and aged normotensives. The A→C variant at position 1166 (A1166C) of the AT1R gene was identified by polymerase chain reaction (PCR) and PCR/restriction fragment length polymorphism (PCR/RFLP) analysis. The frequencies of AC+CC genotypes and 1166C allele of AT1R gene between hypertensives and normotensives were analyzed by Chi Square test. Results The frequencies of AC+CC genotypes and 1166C allele of AT1R gene in hypertensives were higher than those in control (AC+CC genotypes 0.202∶0.097, p<0.05; C allele 0.115∶0.052, p<0.01), the OR(odds ratio)is 2.34(95%CI: 1.15～4.67). More statistically significant of C1166 allele frequency and the AC+CC genotype distribution were obtained in youth between the case and the control when age was hierarchically analyzed (AC+CC genotypes 0.217∶0.088,p<0.01; C allele 0.183∶0.044,p<0.01), the OR reach to 6.82(95%CI: 2.02～23.08). Further more, in the case group, the frequencies of AC+CC genotypes and 1166C allele of AT1R gene in youth were higher than those in middle aged and the aged. Conclusions 1166 AC+CC genotypes and 1166C allele of AT1R gene were related to essential hypertension and could increase the fatalness of suffering from hypertension in youth. It plays an important role in patients who suffered from premature essential hypertension.