A problem on solitary wave induced in a water surface wave field, is introduced for obtaining an analytical solution in a manner of mathematics. By this time, it was recorded offshore at the case of the tsunamis generated by the earthquake in 2011 March 11 in the northwest Pacific. Adding to the above, a hydraulic experiment had been confirmed a couple of solitary waves induced in a field of water surface wave field artificially generated in a basin. Then, a problem is raised to solve in a manner of analytical mathematics for the solitary wave in a water surface wave field under the given conditions.