The MSCs were isolated and cultured from bone marrow of the mice. The mi-196b-5p mimic and mi-196b-5p inhibitor were transfected into the MSCs. The culture medium was collected and the exosomes were separated. The morphology of exosomes was observed under transmission electron microscope.After identification of exosomes by expression of specific markers， the colon cancer CT26.WT cells of the mice were intervened with the exosomes. The colon cancer CT26.WT cells of the mice at logarithmic growth phase after resuscitation were divided into medium group， mimic-NC group， inhibitor-NC group，exosome group， mimic-exosome group and inhibitor-exosome group.The proliferation activities of the colon cancer CT26.WT cells in various groups were measured by MTT assay；the percentages of the colon cancer CT26.WT cells at different cell cycles in various groups were detected by flow cytometry；the apoptotic rates of the colon cancer CT26.WT cells in various groups were detected by flow cytometry； the number of migration and invasion colon cancer cells in various groups was evaluated by Transwell chamber assay.

Compared with exosome group， the proliferation activity， the number of migration cells and invasion cells of the colon cancer CT26.WT cells in mimic-exosome group were decreased （P<0.05）， and the percentage of colon cancer CT26.WT cells at G₁ phase and the apoptotic rate were increased（P<0.05）；the proliferation activity， the number of migration and invasion cells of colon cancer CT26.WT cells in inhibitor-exosome group were increased （P<0.05），and the apoptotic rate was decreased（P<0.05）.

The exosomes derived from MSCs carring a high level of miR-196b-5p can inhibit the proliferation， migration and invasion of the colon cancer CT26.WT cells， and induce the apoptosis.