中文摘要：

连通图G的两个顶点i和j之间的电阻距离rij定义为通过用单位电阻来代替G中的每条边而构造出的电网络N中节点i和j之间有效电阻的阻值。Kirchhoff指标KfG）定义为G中所有点对之间的电阻距离之和。根据图的Laplacian谱理论，得到了由一些完全图按特定方式粘贴构造而成的三类弦图的Kirchhoff指标的计算公式。

英文摘要：

The resistance distance rij between vertices i and j of a connected graph G is computed as the effective resistance between nodes i and j in the corresponding network constructed from G by replacing each edge of G with an unit resistor. The Kirchhoff index Kf（G） is defined as the sum of resistance distances between all pairs of vertices. In this paper, by Laplacian spectra theory, formulae for computing Kirchhoff index of three special classes of chord graphs constructed from a series of complete graphs by pasting them in some certain ways are obtained.