World state of the arts of the conservation of stone monuments is reviewed and the modern conservation program based on conservation science is proposed for the scientific conservation of stone monuments in Korea. The conservation program suggests that the site environment diagnosis, decay diagnosis, petrophysical property analysis, and conservation experiment should always be carefully studied before conservation treatment. It is an up-to-date widely accepted concept in the world of stone conservation science. Our urgent national tasks that should be accomplished for the scientific conservation of stone monuments in Korea are proposed in the following: 1) The stone monument conservation projects should be planned in accordance with 'Conservation Concept of Stone Cultural Properties' and executed in accordance with the proposed 'Conservation Program for Stone Cultural Property' based on conservation science. 2) It is proposed that 'National Institute of Conservation Science for Cultural Properties' be established for systematic conservation research on the tangible cultural properties. 3) The conservation projects of stone monuments should be executed under the control of stone conservation specialist for their quality control. 4) Special national budget should be prepared for quick development of researches on conservation science in Korea.