The non-isothermal crystallization behaviour of pure LLDPE and LLDPE/REDMUD blends was investigated by differential scanning calorimetry (DSC), and the crystallization kinetics was analyzed by three methods, namely the Jeziorny, the Mo and the Ozawa. The results show that an optimal content of REDMUD (lower than10 wt.%) can enhance the kinetic crystallizability of the system because of heterogeneous nucleation, but excessive REDMUD, by physical hindrance, would impair the kinetic crystallizability. In non-isothermal crystallization kinetics, the Ozawa model did not fit well with the crystallization behaviour of these systems, while the Jeziorny and Mo models were found to be applicable. Furthermore, the activation energy ΔE calculated by the Kissinger method for the transport of macromolecular segments to the growing surface of crystal nucleus indicates that REDMUD could significantly reduce the crystallization migration activation energy of these blends.