Abstract: The important factors influencing the preparation of polypropylene/clay nanocomposites were discussed，including the nature of the polymer and clay, melt processing equipment and conditions. Low molecular weight and high M八H grafting degree of polypropylene were beneficial to intercalation，how-ever, once intercalated，high molecular weight and low MAH grafting degree were beneficial to the ex-foliation. The higher the canon exchange capacity(CEC) of the clay, the higher the degree of exfolia-tion was achieved. Twin-screw extruder constituted a good mean for the preparation of polypropylene/clay nanocomposites, which provide proper shear rate to obtain exfoliated structure. However, too high shear rate and too long resident time of the materials in the extruder may cause instability of the exfoliat-ed structure. In addition，an "electric melt pipe" equipped in the twin-screw extruder may promote the formation of exfoliated structure through its electric field. Processing parameters like loading sequence (direct blending or masterhatch method)，screw speed，barrel temperature, and the materials resident time all have impact on the structure of the nanocomposites, especially, high rotating speed of the screws and lower barrel temperature may enhance the exfoliation.

Key words: polypropylcnc, clay, nanocompositc, influencing factor