On the basis of research, the study is to find the use of space in manufacturing plant of reinforcing bar. The main results derived from analysis on these investigations as follows: (1) The optimal capacity of the plant is derived from the stocking and manufacturing quantity of steel bar. (2) The scales of the manufacturing area and the steel bar's stock yard are estimated by applying to function derived from correlation. (3) The numbers of the crane, manufacturing machine and workers are estimated by applying to function derived from correlation.