The present invention relates to polymers having polyolefin segments as the side chain, and uses thereof. The polymers have a structural unit represented by the following Formula (1): wherein A is an olefin polymer having a weight average molecular weight of 400 to 500,000; R is H, an alkyl group, or an aralkyl group; W and Z are each O, HN, or S; and x and y are each 0 or 1, with the proviso that at least one of them is 1. Suitably, the polymer is a polymer having a unit wherein W = 0, x = 1 and y = 0 as the repeating unit, and further contains a polysiloxane block. The polymer of the invention can be applied as an antistatic agent, a cosmetic additive, a releasing agent for toner, a pigment dispersant, a lubricant for vinyl chloride resins, a coating material, an emulsion composition and the like.