Objective:To investigate the dynamic functional connectivity (dFC) of bilateral precuneus at resting-state in obsessive-compulsive disorder (OCD).Methods:Fifty patients with OCD who matched the criteria of ICD-10 and 50 healthy controls (HCs) were examined by the resting-state functional magnetic resonance imaging scanning. Voxel-based whole-brain dFC method was used to analyze the dFC of bilateral precuneus at resting-state in OCD; Pearson correlation analyses was used to analyze the relationship between the abnormal dFC values and clinical symptoms in OCD; support vector machine analyses was used to explore whether abnormal dFC could be used to identify OCD.Results:Compared with HCs, patients with OCD showed decreased dFC values between left precuneus and left medial prefrontal cortex (MPFC) (0.23±0.02 vs. 0.26±0.03, t=-6.23, P<0.05, GRF corrected), left cuneus (0.24±0.03 vs. 0.28±0.04, t=-5.30, P<0.05, GRF corrected), and left paracentral lobule (0.23±0.03 vs. 0.27±0.04, t=-5.36, P<0.05, GRF corrected); and decreased dFC values between right precuneus and left postcentral gyrus (0.23±0.04 vs. 0.27±0.04, t=-5.12, P<0.05, GRF corrected). The decreased dFC values between left precuneus and left MPFC was positively correlated with the total score of Yale-Brown obsessive compulsive scale (Y-BOCS)( r=0.289, P<0.05, uncorrected); the decreased dFC values between right precuneus and left posterior central gyrus was positively correlated with Y-BOCS total scores ( r=0.292, P<0.05, uncorrected) and obsessive subscale scores ( r=0.304, P<0.05, uncorrected). The area under the curve value of the decreased dFC values between right precuneus and left posterior central gyrus was 0.856; the Youden Index was 0.52; the sensitivity was 100%, and the specificity was 52%. Conclusions:The dFC of bilateral precuneus decreases at resting-state in patients with OCD. The abnormal dFC value between the right precuneus and the left posterior central gyrus may have implications to identify OCD.