中文摘要：

图G的剖分值（dissection）是由Randic在1979年引进的一个二维向量（x,y）,记为D（G）= （a（G）,b（G））.Xu等人证明了在所有阶数n≥5的树中,星图K1,n-1具有最大的a（G）和b（G）值.在本文中,我们将对直径为3的n阶树按照剖分值排序,并确定了在直径为4的n阶树中具有最大剖分值的图.

英文摘要：

The dissection of a graph G,denoted by D（G）,is a binary vector（x,y）introduced by Randic in 1979.Xu et al.proved that among all trees of order n≥5,the star K1,n-1 has the maximum dissection number D（G）.In this paper,all the trees of order n with diameter 3 are sorted by their dissections.Among all the trees of order n with diameter 4,the one with maximum dissection is presented as well.