The present invention provides a method for obtaining material information regarding steel sheet for shipping over the entire length of the steel sheet for shipping without spending too much time and effort, providing detailed material information in large volumes to a user through a computer and network, and having the user utilize the same. Specifically, it estimates the mechanical properties of temper rolled steel sheet based on the actual rolling data in a skinpass mill installed at the exit side of the continuous annealing line or galvanization facility and provides the estimated mechanical properties through the host computer and network to the user of the steel sheet. The user can use the estimated material information so as to remove the parts defective in mechanical properties or change the press forming conditions of the steel sheet. Further, the user can feed back information to the steel sheet manufacturer.