For measuring the density of crosslinks in rubber vulcanizates, there are two kinds of methods. The mechanical method leads to a value ν_M(0), whereas the swelling method gives a value ν_S (0). In the ranges of lower crosslink density, the relation ν_M (0)>ν_S(0) is obtained for reasons which are well understood, whereas the inverse relation ν_M(0)<ν_S(0) is established in the range of higher crosslink density for reasons which have not yet been clarified. By introducing improved equations for such vulcanizates at higher crosslink densities, the relationν_M(0)>ν_S(0) was obtained even for the higher crosslink density.