The amino acids content of stems of cotton plants inoculated in the cotiledonary stage was greater for the susceptible variety IAC-12 than for the resistant variety and line respectivelly IAC-RM4 and Acala 3109. For the non inoculated plants of the same age the amino acids content of the stems of the susceptible variety was also greater than the one observed for the resistant plants. The amino acids content of stems of cotton plants inoculated in the stage of three to four true leaves was much greater for the susceptible variety than for the resistant plants. However in the case of non inoculated plants of the same age the amino acids content of the susceptible variety was slighthly lower than the one observed for resistant plants.