Objective To investigate the value ofsomatosensory evoked potentials (SEP) in early diagnosis of cervical spondylotic radiculopathy (CSR). Methods The median nerve SEP (SEPm) was examined in 65 cases of CSR (experimental group), and was compared with 30 controls(control group). All the patients were examined by MRI of the cervical spine which were compared with SEPm. All cases were followed up 12 months, at the same time MRI and SEPm were examined repeatedly. Results The experimental group with CSR had significantly prolonged peak latency (PL) of N11 and N13 wave and interpeak latency(IPL) of wave N9-NI3 within 3 months [( 12.92 ± 0.97), (14.81 ± 1.16), (4.45 ±0.65)ms] and at the 12th month [( 14.20 ± 1.06), ( 16.35 ± 1.75), (5.62 ± 0.88) ms] compared with those of control group[(11.65 ± 0.69), (13.26 ± 0.78), (3.56 ± 0.31 ) ms](P＜ 0.05). The PL of Nll and N13 wave and IPL of wave N9-N13 significantly prolonged at the 12th month compared with those within 3 months.SEPm provided more sensitive modality for the diagnosis[87.69%(57/65 )] of CSR within 3 months than that of MRI [70.77% (46/65)] ( X2 =4.35,P ＜0.05). While there was no significant difference in sensitive between SEPm [90.77%(59/65)] and MRI [81.54%(53/65)] at the 12th month (X2= 1.56,P＞0.05).Conclusion SEP is valuable for the early diagnosis of CSR and may be clinically utilized as a sensitive indicator of CSR.