Abstract: Objective: To investigate the difference of cephalometric analysis between intercuspal position (ICP) and retruded contact position (RCP) in skeletal Class Ⅲ malocclusion patients. Methods: Included in this study were 16 skeletal Class Ⅲ malocclusion patients with functional mandibular displacement. Lateral cephalograms in both ICP and RCP positions were taken and analyzed. Results: The analysis of skeletal indices showed that SNB angle, Angle of convenxity, FMA angle, MP-SN angle, Y axis angle, distance from N-per to Pog, ANB angle, Wits, APDI, Cross overjet and ODI were significantly different between two positions (P<0.001). The analysis of dental indices showed that U1-L1 angle and FMA angle were statistically different (P<0.01 and P<0.001, respectively). The analysis of soft tissue indices showed that the distance from O-M to Pog' and Z angle were statistically different (P<0.001 and P<0.01, respectively). Conclusion: It is important to take and analyze lateral cephalogram in retruded contact position for diagnosing and treating skeletal Angle Class Ⅲ patients with functional mandibular displacement.