One linear and four branched polyvinyl acetate (PVAc) samples were polymeri-zed and fraetionated．Intrinsic viscosities [n]，weight average molecular weight Mw (by LALLS) and GPC ehromatograms were measured for the fraetions．The Mark．Houwink equation for linear PVAc in tetrahydrofuran at 25℃ was found to be [n]=1.62×10-2 M0.698w K and a values for PvAe samples with different degree of branching were also obtained when linear relationships were assumed．From the values of K and a of the branched samples it is possible to talculate the eritical molecular weights Mc's g which eharaeterize the point of separation in molecular weight between the linear and branched moleeules．Different parameters which characterize the degree of branching were ealculated and compared．