Top quark is the heaviest elementary particle within the standard model, this unique property may suggest that top quark play an important role in standard model, or have an opportunity to behave
anomalously. The branching ratio of top quark decays to bottom quark and W boson is close to unity, thus a study on its rare decay as well as anomalous interactions of top quark can be served as a probe to physics beyond the standard model. Several analysis targeting top quark rare decay and beyond standard model interactions from CMS will be introduced in this report.