Purpose: Evaluating the bowel peristalsis function in Crohns disease(CD)with MR bowel motility imaging.Methods: A total of 75 CD patients(42 active and 33 inactive further subgrouped by segment stenosis)with 100 segments lesion and 25 controls were enrolled.In motility color map,average values of motility amplitude of total bowel tract(T)and focal tract,including lesion segment(L,La for stenosis group,Lb for non-stenosis),control segment(C1 for patient,C2 for control),expand segment(E),L/C1,E/C1 were measured.One-way ANOVA,Student t tests and ROC curve were performed.Results: Ta and Ta+b in active group(8.59,7.71)were higher than T in control(7.35),Tb in active(7.27)and T in inactive(Ta6.61,Tb6.87,Ta+b6.95).Statistical difference was found among La,Lb within groups.La in active group(10.66)were significantly higher than C1a(6.28).Lbs in both patient groups and La in inactive group were significantly lower than C1.La+b/C1 and E/C1 were statistically different among groups.L/C1 incontrol group was difference from other groups.La/C1 inactive group was increased than other groups.Lb/C1 was decreased and was difference between patient groups.ROC analysis showed sensitivity was 80%and specificity was 50%of L and sensitivity was 80%and specificity was 75%of L/C1 for positive diagnosing non-stenosis active CD.The sensitivity was 83.3%and specificity was 90.5%of L/C1 for positive diagnosing non-stenosis inactive CD.Conclusion: Bowel motility MRI is valuable to evaluate bowel peristalsis function and distinguish CD activity.