Objective To investigate the difference of temporary memory system and brain biochemical metabolites between patients with depressive obsessive-compulsive disorder and simple obsessive-compulsive disorder. Methods From June 2017 to June 2018, 31 patients with simple obsessive-compulsive disorder, 33 patients with depressive obsessive-compulsive disorder and 25 healthy volunteers were selected as subjects. The temporary memory ability of the three groups was tested by n-back, Stoop color association test and digital breadth test. Three brain sublimation metabolites, N-acetylaspartate acid (NAA), choline complex (Cho) and creatine (Cr), were detected by proton magnetic resonance pop (1H-MRS) in bilateral prefrontal white matter, anterior cingulate cortex and anterior cingulate cortex. The ratio of NAA/Cr and Cho/Cr was calculated with Cr as reference material. Results The scores of Yale-brown obsessive-compulsive severity scale (Y-BOCS) and Hamilton depression rating scale 24 (HAMD24) in the patients with simple obsessive-compulsive disorder and depression obsessive-compulsive disorder group were significantly higher than those in the healthy control group, and the scores of HAMD24 in the patients with depression obsessive-compulsive disorder group were significantly higher than those in the patients with simple obsessive-compulsive disorder group, with statistically significant difference (P 0.05). Compared with the healthy control group, the NAA/Cr value of bilateral prefrontal white matter in the simple obsessive-compulsive group and the depression obsessive-compulsive group was significantly lower, and the difference was statistically significant (P<0.05). Conclusions Both patients with simple obsessive-compulsive disorder and depressive obsessive-compulsive disorder had speech memory impairment and bilateral prefrontal white matter nerve function decline, while depressive obsessive-compulsive disorder patients also had central executive memory impairment. Key words: Obsessive-compulsive disorder; Depressive disorder; Memory, short-term; N-acetylaspartate; Choline complex; Creatine