In this work effects of plant regulators on cotton Gossypium hirsutum L. cv. IAC-17 were studied, through growth analysis and productivity measures in plants subjected to different dosages of plant regulators applied at various stages of growth. To discover the growth, production and agronomic characteristics of the cotton plant and the technological characteristics of the fibers, under the effect of plant regulators, an experiment, under field conditions was carried out in Piracicaba (SP) on the 1978/79 crop. Cotton was treated with 84, 167 and 250 ppm DPC; 250, 350 and 450 ppm CCC and 1670, 3340 and 6680 ppm CEPA, at respectively 5, 65 and 143 days after germination. The results show that DPC and CCC tended to reduce plant height and crown diameter. DPC applications did not affect growth analysis parameters while 250 ppm CCC reduced foliar area and the" dry matter weight of cotton. The leaf area index was reduced during 28 days, with 250 ppm and 350 ppm applications; the lowest concentrations reduced the photosynthetic efficiency of the plants and the highest concentration of CEPA and CCC tended to reduce the number of boll number of seeds and wool weight. CCC 350 ppm apparently increased the average bool weight while CEPA 6680 ppm tended to reduce it. With each treatment the seed weight and fiber percentage sampled in 50 g of seed as well as the weight of seeds were not affected by CCC, DPC and CEPA applications. The technological characteristics of the fibers were not affected by plant regulators.