The resistance distance between any two vertices of G is defined as the network effective resistance between them if each edge of G is replaced by a unit resistor. The Kirchhoff index Kf( G ) is the sum of resistance distances between all the pairs of vertices in G . We firstly provided an exact formula for the Kirchhoff index of the hypercubes networks Q n by utilizing spectral graph theory. Moreover, we obtained the relationship of Kirchhoff index between hypercubes networks Q n and its three variant networks l ( Q n ) , s ( Q n ) , t ( Q n ) by deducing the characteristic polynomial of the Laplacian matrix related networks. Finally, the special formulae for the Kirchhoff indexes of l ( Q n ) , s ( Q n ) , and t ( Q n ) were proposed, respectively.