Objective To investigate the prevalence of scoliosis and congenital heart disease(CHD)and their correlation among children and adolescents of Drung nationality in Yunnan Province.Methods A cross-sectional survey was conducted in November 2022 among all Drung school-aged children and adolescents aged 5-18 years in Gongshan Drung and Nu Autonomous County,Yunnan Province.Visual inspection,Adams for-ward flexion test,and trunk rotation angle(ATR)measurement were comprehensively used for school prelim-inary screening of scoliosis.Individuals who tested positive in the school preliminary screening underwent fur-ther X-ray examination for auxiliary diagnosis.Cardiac auscultation and echocardiography were used for school preliminary screening of CHD.The personal information of the screening subjects,the screening results,etc.were recorded.The prevalence of scoliosis and CHD among children and adolescents of the Drung nationality and the relationship between the two diseases were statistically analyzed,and the positive predictive value of school-based scoliosis screening and its influencing factors were also analyzed.Results A total of 1 036 chil-dren and adolescents of Drung nationality were enrolled,with a mean age of(10.72±3.75)years,icluding 542 males and 494 females.A total of 45 subjects tested positive for scoliosis in the school preliminary screening,with a preliminary positive rate of 4.34%.A total of 22 cases were finally diagnosed with scoliosis,with a prevalence rate of 2.12%.Among them,21 cases were idiopathic scoliosis(accounting for 95.45%),and 1 case was congenital scoliosis(accounting for 4.55%).The prevalence rate was higher in females(2.83%)than that in males(1.48%),higher in the 10 to 18-year-old group(2.30%)than that in the 5 to<10-year-old group(1.87%),and higher in the secondary school group(2.78%)than that in the primary school group(1.78%),hut there were no statistically significant differences(P>0.05).Most idiopathic scoliosis cases were mild(Cobb angle 10° to<20°,90.48%)and classified as Lenke type Ⅴ(57.14%).Two cases of CHD were confirmed,both of which were atrial septal defects,with a prevalence rate of 0.19%.The co-occurrence rate of idiopathic scoliosis and CHD was 4.76%(1/21).The positive predictive value of school-based scoliosis pre-liminary screening was only 48.89%.When the BMI was<18.5 kg/m2,the positive predictive value was sig-nificantly higher than that for BMI≥18.5 kg/m2(P<0.05).Conclusion The prevalence rate of scoliosis a-mong adolescents of the Drung ethnic group in Yunnan Province is 2.12%,predominantly idiopathic scoliosis,with Lenke type V being the most common classification.The prevalence rate of congenital heart disease is 0.19%.BMI is a significant influencing factor for the positive predictive value of school-based scoliosis prelimi-nary screening.