ABSTRACT Objectives To study the evaluating consistency of the hip by sonographers with different levels of experience using Graf’s method under different conditions. Methods A total of 240 hips of 120 infants evaluated with Graf’s method were randomly divided into A, B, C, D groups according to 3 different experienced sonographers whether to use additional equipments or not based on their knowledges: Group A: Infants were examined the hips only using ultrasound by sonographer ① and ②; Group B: Infants were examined using ultrasound assisted with dimple memory foam mattress and metal immobilization device by sonographer ① and ②; Group C: Infants were examined the hips only using ultrasound by sonographer ② and ③; Group D: Infants were examined using ultrasound assisted with dimple memory foam mattress and metal immobilization device by sonographer ② and ③; The evaluating consistency were statistically compared with measurements of angle. Results The mean difference of ? angle measurement in four groups was 0.45°, -0.10°, 0.42° and -0.09° respectively. The inter-examiner agreement rate of diagnosing hip classification was 76.7%, 84.6%, 55.8% and 72.3% respectively. The difference, was not statistically significant between Group A and B, was statistically significant between Group C and D (X2=7.26，P=0.042). The diagnostic agreement of Graf''s sonographic classification between two sonographers in Group B were good (Kappa = 0.76, 95%CI: 0.44～0.81).The inter-examiner agreement rate in the diagnosis of normal and abnormal hip were 88.3%, 93.3%, 78.3% and 85.0% respectively. The difference, was not statistically significant between group A and B, was statistically significant between group C and D (X2=8.27，P=0.013). The diagnostic agreement of abnormal hip between two sonographers in Group B were good (Kappa = 0.82, 95%CI: 0.70～0.95). Conclusions The consistency of evaluating the hip is irrelevant to the conditions, but is related to examiner experience and additional equipments.