Objective To explore the relationship between magnetic resonance imaging (MRI) signs and clinical features of carpal tunnel syndrome (CTS). Methods 230 patients with CTS (CTS group) who were admitted to wrist department of the hospital from January 2018 to December 2019, and 30 healthy volunteers (control group) were selected as the research subjects. General data and clinical data of patients with CTS were collected. The electrophysiological examination and MRI examination were performed in both groups. The differences between the two groups were compared. The correlation between MRI parameters and clinical parameters was analyzed.Results The median nerve motor conduction velocity (MCV), sensory conduction velocity (SCV), compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) in CTS patients were significantly lower than those in control group, while distal motor latency(DML) and sensory latency (ML) were significantly longer than those in control group (P＜0.05). MRI examination showed that crosssectional images of carpal tunnel structure were the best. T1WI and T2WI showed that the carpal tunnel sites where median nerve entered were thickened and swollen. The carpal tunnels were compressed and flattened, especially at the level layer of hook bone. The median nerve crosssectional area (CSA) of postular bone, median nerve swelling rate (MNSR) and median nerve flat rate (MNFR) in CTS patients were significantly higher than those in control group (P＜005). CSA was negatively correlated with SCV in postular bone (P＜0.05), MNSR was positively correlated with static twopoint discrimination and SNAP (P＜0.05), while negatively correlated with SCV (P＜0.05). Conclusion MRI examination can determine organization structure abnormalities of CTS. And there is certain relationship between MRI parameters and clinical electrophysiological indexes.