Objective To explore the characteristics of sagittal spino-pelvic parameters in patients with chronic low back pain and their relationship with chronic low back pain. Methods From Jul. 2019 to Jun. 2021, 249 patients with chronic low back pain (LBP group) and 86 physical examination adults without low back pain symptoms (control group) were selected as subjects in The First Affiliated Hospital of Naval Medical University (Second Military Medical University). The general data of the 2 groups were collected, the thoracic kyphosis (TK), lumbar lordosis (LL), LL-TK, sacral inclination (SS), pelvic inclination (PT), pelvic incidence (PI), SS-PT, LL-PI, sagittal verticalaxis (SVA) and other sagittal parameters were measured on the full-length anteroposterior and lateral X-ray films of the spine, and the differences between the 2 groups were observed. Results There were no significant differences in age, gender or body mass index between the 2 groups (all P>0.05). TK in the LBP group was higher than that in the control group, while LL-TK, SS, PI and SS-PT in the LBP group were lower than those in the control group (all P<0.05). There were no significant differences in LL, PT, LL-PI or SVA between the 2 groups (all P>0.05). The types of lordosis were mainly type 2 (SS<35°, small LL, the apex of lumbar lordosis is located in L₄) in the LBP group and control group, accounting for 70.7% (176/249) and 57.0% (49/86), respectively. There was no significant difference in the composition ratio of lordosis types between the 2 groups (χ²=6.161, P=0.104). Conclusion The sagittal spino-pelvis parameters of patients with chronic low back pain are different from those of adults without low back pain symptoms. Large TK, small SS, and small PI are more common in the low back pain patients, suggesting that this particular pattern is related to chronic low back pain.