Long branching in poly (vinyl alcohol) (PVA) was quantitatively determined from measurements of the intrinsic viscosity and gel-permeation chromato-graphy of derived poly(vinyl acetate) (PVAc) according to Kurata’s method. The average number of branch points per unit molecular weight, λ3, was observed to lie in the range of 10−6—10−5 for PVA obtained from PVAc polymerized at 60°C in bulk. The tendency for the values of λ3 to increase with the increase in the conversion of polymerization of the parent polymer was found to be in close agreement with that expected from the kinetic equation proposed in our previous paper.