A system analyzing method for analyzing a transaction system includes firstly extracting a transaction, which is processed by a plurality of servers cooperating with each other in the transaction system, from a message log in which parameters of messages have been subjected to name merge, by using a transaction model which is generated from a set of messages transmitted between the servers during processing of the transaction, and secondly extracting a transaction from a message log from which no transaction is extracted in the firstly extracting, by using a value of a parameter inherited between the servers among parameters in messages included in the message log.