Study Design. Retrospective study. Objective. To determine the correlations and age-related changes of cervical sagittal parameters in adults without obvious cervical spinal disease. Summary of Background Data. Cervical sagittal parameters play essential roles in the pathogenesis and therapy of cervical spinal diseases. However, few studies have investigated the correlations and age-related changes of cervical sagittal parameters. Methods. The enrolled participants were divided into three age groups and their cervical sagittal parameters were collected. Correlations and age-related changes of these parameters were analyzed. Results. Significant differences in the C2-C7 angle, center of gravity of the head-C7 sagittal vertical axis (CGH-C7 SVA), C2-C7 SVA, neck tilt (NT), and thoracic inlet angle (TIA) were found among the three age groups. Pearson correlation analysis showed positive correlations between the C0-C2 angle and CGH-C7 SVA, C0-C2 angle and C2-C7 SVA, C2-C7 angle and T1 slope, C2-C7 angle and TIA, CGH-C7 SVA and C2-C7 SVA, C2-C7 SVA and T1 slope, T1 slope and TIA, and NT and TIA as well as negative correlations between the C0-C2 angle and C2-C7 angle, C2-C7 angle and CGH-C7 SVA, and C2-C7 angle and C2-C7 SVA. Paired t tests showed significant changes in the C2-C7 angle in groups I and II, and in the CGH-C7 SVA and C2-C7 SVA in all age groups with increasing age. Conclusion. The results indicate that cross correlations exist between different cervical sagittal parameters in adults without symptoms of cervical spinal disease, and the lower cervical curvature and SVA change obviously with increasing age.