Background In-stent restenosis (ISR) has become one of the most challenging problems in patients with coronary heart disease. At present, using non-invasive methods to assess ISR is a hol topic. In this investigation we attempted to explore the potential of magnetocardiography (MCG) in diagnosis of in-stent restenosis.Methods MCG was analyzed in 52 patients with coronary artery disease for three times: before stenting, one month and 7 months after successful intracoronary stenting.Results The average classification of total maps (ACTM) and the ratio of abnormal maps (RAM) were Iower in 1 month after intracoronary stenting compared with that obtained before stent planting (2.91 vs 2.52, 65.74% vs 42.80%, P＜0.01),while complex ventricular excitation Index (CVEI) increased from -42.63 to -20.05 (P＜0.01). In ISR subgroup (n=16),RAM decreased in 1 month after intracoronary stenting compared to it before stenting (68.99% vs 45.26%, P＜0.05).ACTM increased in 7 months compared to that obtained in 1 month after stenting (3.15 vs 2.51, P＜0.05). According to the ROC curve, ACTM showed its unique diagnostic value in restenosis patients. The sensitivity and specificity of ACTM were 80.0%, 69.40%, respectively. Its positive predictive value and negative predictive value were 54.6% and 88.5%,respectively.Conclusions After successful intracoronary stenting, most parameters of MCG were improved. ACTM was of prognostic value in diagnosing ISR.