Abstract: ObjectiveTo investigate the heritability of the blood pressure in two age groups by twins population.MethodsAccording to the standard quest ionnaire,information on sociodemographic and environmental variables were obtained from 1 101 pairs twins aged 8-64 years,by trained interviewers,the blood pressure was measured by manometer of mercury column.ResultsUnder the classic twin model,the intra-difference of DZ is larger significantly than that of MZ;the intradifferene of both kind twins increased with age;Furthrmore,heritability was calculated according to the method suggested by Holziger,and the total heritability of the SBP is equal to 0.278 and DBP is equal to 0.368.ConclusionGenetic factors correlate significantly with blood pressure.