The aim of this study is to investigate present situation about occurrence of surplus classrooms by the merger and abolition of rural elementary schools, and to deduce basic architectural data for efficient utilization. It was examined based on the analysis of using pattern and interview of teachers of modernized elementary model schools. The occurrence ratio of surplus classrooms was about 30 to 60 percentages among seven investigated schools, the ratio was gradually increasing. Most of them were nearly leaving without certain practical use because of inaccessibility and low degree of diversion. The characteristic about diversion of surplus classroom was shown to change from special or learning room to living-related room and management-related room in order, finally, it was used a room for child care with a lapse of time. Long-tenn and continuous data accumulation for diversion and utilization of surplus classroom should be required.