Aim To evaluate the diagnostic value of high resolution nuclear magnetic resonance imaging (HR-MRI), oxidized low density lipoprotein (ox-LDL) and lipoprotein associated phospholipase A2 (Lp-PLA2) in serum for the prognosis of patients with middle cerebral atherosclerotic stenosis (MCAS). Methods From August 2015 to August 7,6 patients (stenosis group) who were diagnosed as cerebral infarction by neurology department, and diagnosed as MCAS by transcranial Doppler (TCD), magnetic resonance imaging (MRI), magnetic resonance angiography (MRA) and clinical manifestations were selected, and another 90 patients with normal physical examination were selected as control group. The parameters of plaque size and plaque load were obtained by HR-MRI vascular wall imaging technology. Enzyme linked immunosorbent assay (ELISA) was used to detect the levels of ox-LDL and Lp-PLA2 in serum. After 3 months of treatment, the prognosis was assessed by modified Rankin Scale (mRS scores ＞2 was poor prognosis), and the patients were divided into 85 cases of poor prognosis group and 21 cases of good prognosis group. Pearson method was used to analyze the correlation between plaque size, plaque load, levels of ox-LDL and Lp-PLA2 in serum and mRS scores. Receiver operating characteristic (ROC) curve was used to analyze the diagnostic effect of HR-MRI combined with serum ox-LDL and Lp-PLA2 on the prognosis of patients with MCAS. Results Compared with the control group, the plaque size, plaque load, serum ox-LDL and Lp-PLA2 levels in the stenosis group were significantly increased (P＜0.05). Compared with the good prognosis group, the plaque size, plaque load, serum ox-LDL and Lp-PLA2 levels in the poor prognosis group were significantly increased (P＜0.05). Plaque size, plaque load, serum ox-LDL and Lp-PLA2 levels were all positively correlated with mRS scores (r＝0.5,0.4,0.7,0.679, P＜0.05), and have high diagnostic efficiency, the combined detection was more effective in predicting the prognosis of patients with MCAS. Conclusion Plaque size, plaque load, serum ox-LDL and Lp-PLA2 levels have high diagnostic efficacy for the prognosis of MCAS patients, and the diagnostic efficacy of combined detection is higher, HR-MRI vascular wall imaging combined with serum ox-LDL and Lp-PLA2 levels has certain reference value for clinical diagnosis of MCAS patients.