a communication path estimation method for estimating a communication path in a network in which communication is performed by forwarding packets from a plurality of transmission source nodes to a plurality of transmission destination nodes through a plurality of nodes , the method has obtaining , by a computer , path information of a plurality of paths , extracting a path in which a number of lost packets out of packets flowing in the extracted path is a predetermined value or more on the basis of the path information , choosing a pair of adjacent nodes included in the extracted path , and outputting a hypothesis that a static path is set from a first downstream node to a second downstream node when the first downstream node being included in a plurality of paths connected to a plurality of destination nodes and a first upstream node is the same with a second upstream node .