Objective:To study the prevalence and major risk factors of low blood pressure in the rural area of Maoxian County in Sichuan Province.Methods: A cross-sectional study of low blood pressure was conducted using sampling survey of blood pressure in Maoxian County.Low blood pressure was defined for systolic (SBP) and diastolic (DBP) pressure according to child blood pressure (10-14 years:SBP ≤80 mmHg or DBP≤50 mmHg,1 mmHg=0.133 kPa) and adult low pressure criteria (over 15 years:SBP≤90 mmHg or DBP≤60 mmHg).Results: The prevalences of low blood pressure for males and females were 8.2% and 12.2%,respectively.Prevalences of low blood pressure were 17.3%,12.3%,4.8%,and 5.5% for age groups 10-,20-,40-,and 60-,respectively.Logistic regression showed that the age (OR=0.566,95%CI 0.406-0.789),gender(OR=1.999,95%CI 1.171-3.411) and nationality (OR=6.967,95%CI 2.322-20.905) were correlated with low blood pressure.Conclusion: Younger age is the risk factor of low blood pressure.Females and non-Qiang minorities have higher risk for low blood pressure,which offers clues for further study the causes of low blood pressure.