However, small molecular or oligomeric additives that are currently used in PE surface modification may be removed readily by evaporation, dissolution, or wear during processing, storage or in use due to weak bonding of the additive with the matrix polymer. To overcome this shortcoming and thus to gain long-term stable effect, a number of amphiphilic macromolecular surface modifiers for PE surface modification have been introduced by Bergbreiter [12] and [13], Wesslén [14]. Based on our early works [15] and [16], we brought up a novel preferred-diffusion macromolecular surface modifier. An ideal additive of such category used for surface modification is believed to meet the following requirements: (1) the chemical structure and molecular architecture should enable the additive to preferentially diffuse to or enrich on the surface; (2) a small amount of additive can remarkably change the surface properties and gain a stable surface modification effect while leaving the bulk polymer properties intact; (3) it should be easily prepared or widely available commodity with low cost.