Abstract: In order to explore the prevalence and associated risk factors of low back pain(LBP),an epidemiological investigation was performed in a cohort of 1588 secondary-school adolescents using a LBP questionnaire made by our own.There were 811 male and 747 female subjects 12 through 19 years of age,with an average age of 14.9years.The results showed that 55.1% of the students reported ever experiencing LBP.Forty-three percent of the students reported experiencing LBP within the previous 12 months,with 40.2% and 45.6% of male and female students,respectively(P<0.05).Seventeen percent of those with LBP reported that the back pain was sufficiently severe to force them to miss school or keep them from playing sports.6.6 percent of the students indicated LBP sought medical attention.The associated risk factors of LBP were the history of back in jury(OR=2.75),≥10 hours of sitting time(OR=1.60),incorrect sitting posture(OR=1.56),BMI≥22(OR=1.45)and using 2 or more sleeping pillows(OR=1.32).It is concluded that LBP in secndary-school students has been a serious public health problem to which more attention should be paid and prevention research must be strengthened.