This paper presents a method of locating a crane on a construction site using mathematical techniques. The optimum location and choice of the crane on a site is seen as one of the most important parts of construction planning (FURUSAKA 1984). In large projects, many buildings will be constructed using many cranes. However, dicision-making during planning and managing stages, such as construction method, the number of cranes, etc., are still mostly depended on "experience or "intuition". It proposes the algorithm which can define the least expensive cranage cost by calculating the combined use of a number of cranes and construction method. Conclutions are drawn as to the relevance of the application of the model to construction projects.