Abstract: ObjectiveTo study effect of dietary factors on bone density among school-age children.MethodsTotally 2 046 primary school children of grade 1 to 6 were selected in Tangshan city.Factors related to bone health and diet intakes were investigated and ultrasonic bone mineral density measurement was conducted among the children.The data were analyzed with SPSS 13.0 software.ResultsThe average bone speed of sound(SOS)level was 1 530.2±21.0 m/s,with a decrese of 540.4±22.3 m/s to 1 521.9±20.0 m/s from 6 to 9 years old and an increase to 1527.4±22.5 m/s at the age of between 10-13.The SOS level was within the 95% reference range for the children with intakes of wheaten food of 200-400 g/d,soy bean products of 25-24 g/d,milk products of 200-400 g/d,leafy vegetables of 75-124 g/d,calcium of 50%-149% adequate intake(AI),and phosphorous of 50%-149% AI.The SOS level was higher than the reference range for the children with intakes of soy bean products of 50-99 g/d,leafy vegetables of 50-74 g/d,and calcium of 150%-200% of AI.ConclusionChildren's dietary intakes have effect on bone density level.The improvement of dietary behavior can promote children's bone density.