The blends of poly(vinylidene fluoride) (PVF2) and methyl methacrylate-styrene radom copolymer (MS) of different styrene (St) mol％ were investigated．This paper deals with the crystallization behaviors and mechanical properties of PVF2/MS blends．It was found that while the MS content increases in the blends．the crystallization of PVF2，their melting points and the rates of crystallization decreases，the spherulites and their sizes become imperfect and smaller．The influence of MS-90 (St mol％ is 10) is grea+er than that of MS-80 (St mol％ is 20)． The mechanical properties of PVF2／MS-90 and PVF

／MS-80 are vastly different due to their miscibility．For the miscible system of PVF

／MS-90 as the PVF2 increases to 50％(Wt)，the blends go through the transition from the amorphous to the semi-crystalline and their me-cbanical properties accordingly display discontinuous．For the semi-miscible system of PVF2/MS-80，the blends are brittle when PVF2 is less than 50％，whereas when the content is over 60％，a concerted effect can be observed that heir elongation is vastly greater than that of pure PVF2 while the strength of the blends are much the same as pure PVF2．