Linear Low Density Polyethylene (LLDPE) is used widely in applications like lamination and agricultural films, as well as a modifier for Low Density (LDPE) and High Density (HDPE) Polyethylene. LLDPE is made by polymerizing ethylene with small amounts of Alpha-Olefins typically 1-butene, 1-hexene or 1-octene, to form a copolymer in a low pressure process. The LLDPE used in this book contained 93 - 100% ethylene by weight and 0 - 7% by weight 1-hexene as Comonomer. The melt strength of LLDPE can be modified by introducing long chain branching (LCB) to its backbone and there are several techniques to accomplish that. In this work, free radicals are formed by adding Benzophenone (BP) as a photo-initiator and by irradiating solid sheets of the LLDPE resin by using a UV lamp. As a result, LCB affects the rheological properties and this has been studied in this book.