Abstract: Based on connectionmatrix, this paper presents a newmethod to calculate the minimumpath sets between two nodes in a network, and gives a precise proof of it. By this method, the rows corresponding to the input nodes and the columns corresponding to the output nodes in the general connection matrix of the network are eliminated, and the path calculation in the network is transformed to the operation of connection matrix determinant. The method is applicable to any oriented, nonoriented or mixed networks.