On the basis of research,the study is to find function and utilization of manufacturing plant of reinforcing bar. The main results derived from analysis on these investigations as follows : (1) Warehouses, offices, or rest stations are placed on the site of many plants. (2) Similar results are derived from the process chart-product analysis and the process chart-man analysis on many plants. (3) Plans of manufacturing plant of reinforcing steel are composed of four zones: those for keeping steel bars, installing machinery, placing reinforcing bars, and truck's transporting paths.