Deemo Chen, grade 11 student. Barstow School – Ningbo Campus. Abstract 1I/2017 U1 (‘Oumuamua), a recently discovered asteroid in a hyperbolic orbit, is likely the first macroscopic object of extrasolar origin identified in the solar system. This paper mainly gives reasons why ‘Oumuamua should be a comet, by explaining three unusual behaviors of ‘Oumuamua which are unnormal ratio, strange track eccentricity, and Peculiar Acceleration; disproving four main hypothesizes to say ʻOumuamua is not a comet, then provide an evidence of reflectivity of surface of ʻOumuamua to prove ʻOumuamua in a regular interval of comet group.