Abstract: A new method of pret reatment of jute f iber is put forward , where MPP emulsion was used in the pret reatment . Several issues were studied including the effect s of pret reatment of jute f iber with alkali solution on themoisture and thermal stability as well as the effect s of pret reatment of jute f iber with alkali solution and combinationof alkali solution and MPP emulsion on the mechanical properties of the jute f iber mat reinforced polypropylene. Theresult s show that the moisture and thermal stability of the jute f iber are improved and the mechanical properties ofjute f iber mat reinforced polypropylene are obviously increased af ter t reating with alkali solution. The mechanicalproperties of the composites are even better af ter t reating with combination of alkali solution and MPP emulsion.