摘要
本文证明了３－连通非偶图的色多项式根２的阶为１；满足一定条件的非３－连通非偶图的色多项式根２的阶是图的非偶块和非偶可分块数．从而，把色多项式Ｐ（Ｇ）中１的阶是图Ｇ的非平凡块数这一结果进一步加以推广．
In this paper, it was proved that the multiplicity of the root 2 in the chromatic polynomial of 3-connected non-even graph is 1 ; and it is showed that the multiplicity of the root 2 in the chromatic polynomial of non-3-connected graph with definite conditions is equal to the number of non-even blocks and non-even separable blocks. Therefore, it was spreaded that the multiplicity of the root 1 in the chromatic polynomial of a simple graph G is equal to the numble of nontrivial blocks in G.
