The experiments were conducted at the Research Farm of Dusty Acre, Department of Plant Breeding and Genetics, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur during kharif 2013. The experiment was laid out in Randomized Block Design with three replications. The experiment consisted of 7 treatments comprised to different concentration of plant growth retardants viz., Paclobutrazol (40 SC 60 ml, 75 ml, 90 ml and 23 SC 105.6 ml, 132 ml) and Chlormequat chloride (50% SL 500 ml). Observation on various physiological growth determinants and biochemical estimation of soybean were recorded. The leaf area index significantly increased up to 75 DAS and decline steadily towards maturity. The LAI and LAD were found to be maximum in Chlormequat chloride and were recorded to be lower in paclobutrazol. CGR and RGR were significantly influenced by the application of Chlormequat chloride. The minimum CGR and RGR were noted under treatment Paclobutrazol (40 SC @75 ml/ha). The highest protein content (%) was obtained in Chlormequat Chloride 50% SL 500 ml/ha (35.22), while, the lowest protein content (%) was estimated in control (34.37). The maximum oil (%) was noted in Chlormequat Chloride 50% SL 500 ml/ha (16.02) and control (14.40) had the lowest value as compared to all others. Significantly maximum seed oil yield was exhibited by Paclobutrazol (40SC @75 ml/ha) (1.16) while, minimum Seed oil yield was observed in control (0.87).