In our previous report, it was discovered that the polycondensation of 9-amino-nonanoic acid follows second order from the beginning up to the extent of reaction, p, around 99%, and after which the reaction changes rapidly to third order. In this paper, we wish to report that this change of the reaction order from second to third occurred also in the polycondensation of 6-aminocaproic acid and 11-amino-undecanoic acid. The transition region lay again at p around 99%. It may be concluded that this is a general rule in the polycondensation of the ω-amino-acids(monomers of the A-B type),and the controversial results that appeared in the literature may be cleared up by our experiments.