【Objective】To investigate the effect of P-selectin on the intestinal tumorigenesis in the 15，24-week-old Apc Min/+ mice.【Methods】Male Apc Min/+ mice were mated with female P-selectin knockout（P-sel -/- ）mice to generate A M/+ Ps -/- mice. The diameters and numbers of the intestinal tumors in the intestines of Apc Min/+ and A M/+ Ps -/- mice were measured using an inverted microscope. The tumor volumes were measured using the following equation：volume = 0.52 ×（length × width 2 ）.【Results】There were no significant difference between the volume and number of intestinal tumor in 15-week-old Apc Min/+ mice and 15-week-old A+ P- mice. The volume and number of intestinal tumor were significantly increased in 24-week-old A+P- mice compared to 24-week- old ApcMin/+ mice. P-selectin deletion significantly prolonged the survival time of ApcMin/+ mice.【Conclusions】P-selectin deletion promotes the intestinal tumorigenesis in the 24-week-old ApcMin/+ mice.