LDPE/ultrahigh molecular weight polyethylene (UHMWPE) blends were prepared through a pan-milling reactor in solid state at ambient temperature. The changes of structure and properties of LDPE/UHMWPE blends were investigated by melt flow index, mechanical properties, scanning electronic microscope (SEM), differential scanning calorimetry (DSC), and wide-angle X-ray diffraction. SEM photos showed that after pan-milling treatment the dispersed approximately equiaxed UHMWPE particle became rodlike. DSC measurement illustrated that after pan-milling treatment, the peaks of UHMWPE shift to lower temperatures while the peaks of LDPE kept stable. The more content of UHMWPE led to more evident shift. X-ray diffraction analysis showed that the crystallinity of milled LDPE/UHMWPE blends decreased lightly, but the crystalline grain size decreased only for high content UHMWPE blends. The tensile properties of pan-milled LDPE/UHMWPE blends also achieved significant improvement after pan milling treatment. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2487-2493, 2013