Abstract The non-isothermal crystallization kinetics of silane crosslinked polyethylene (SXPE) and dicumyl peroxide (DCP) modified polyethylene (DMPE) were studied by differential scanning calorimetry at different cooling rates. Three methods, namely, the Avrami, the Ozawa, and the Mo, were applied to describe the crystallization process of virgin LLDPE, DMPE and SXPE under non-isothermal conditions. The values of half-time of crystallization t1/2, and the parameter Zc in the Avrami method which characterize the kinetics of non-isothermal crystallization, show that the crystallization rates of virgin LLDPE and DMPE are faster than that of SXPE at the same cooling rate, and crystallization rates of all samples increase as the cooling rate increases. The Ozawa model is also suitable to describe the process of the non-isothermal crystallization kinetics of all samples. In the Mo method, it has been found that the F(T) values of virgin LLDPE and DMPE are lower than that of SXPE, meaning that the crystallization rate of virgin LLDPE and DMPE is faster than that of SXPE.