The present study tried to assess the effects of modified apple polysaccharide (MAP) on colitis associated carcinogenesis and the expression of Mucin 1(MUC1). One hundred and twenty 5-week-old male ICR mice were used. The control mice were just administrated with saline, and the rest mice were injected intraperitoneally with 1, 2-dimethyl-hydrazine (DMH) and dextran sodium sulfate (DSS). In the 7th week, the mice in MAP-treated groups were bred with the basal diets mixed with different doses of MAP (w/w: 1.25%, 2.5% and 5%) for 13 weeks. The pathological findings demonstrated that: in the 20th week, adenocarcinoma and/or adenoma occurred in the colons of all the mice in model group. MAP treatment decreased the incidence of colorectal cancer significantly. In the early phase of inflammation, MUC1 expression in colonic mucosa had no significant changes. However, when the inflammation developed and tumor formed, MUC1 expression increased remarkably (P < 0.01). And the MAP treatment (especially at the dose of 5%) reduced MUC1 expression significantly. These data suggested that MAP could prevent against colitis associated colorectal cancer in ICR mice effectively, and MUC1 may be a potential therapeutic target in colorectal cancer prevention and treatment. Copyright © 2018 Elsevier B.V. All rights reserved.