This study describes a new system of placing the patterns of childrens clothes upon the fixed area of cloth. It is based on the theory of magic square in mathematics, with a view to inproving the work of the factory where ready-made clothes are manufactured. The merits of the system are: 1. to facilitate the cost account. 2. to enhance the efficiency of production, 3. to produce more variety of sizes, 4. to economize the clothing material, 5. and to standardize the designation of the size.