The aim of present study was to evaluate the appropriate concentration of plant growth regulator i.e. (10^-3 M) of the IAA on the stem growth of Phaseolus vulgaris (Rajma) over the control. Seeds of Phaseolus vulgaris (Rajma) were sown in sandy loam soil in field plots (A & B). Plot-A of legume crop was treated as control and not sprayed with growth regulator. Plot-B was sprayed with IAA solution of (10^-3 M) concentration daily. It was observed that IAA was found most effective in (10^-3 M) concentration for the stem & root growth patterns of Phaseolus vulgaris (Rajma).