A B S T R A C TIncreases in room temperature may significantly influence the germination process of several plant species. It can directly interfere directly with physiological, biochemical and other activities, thus altering the maximum seed capacity to activate seedling emergence, as well as the morphological Plants. The objective of this study was to evaluate the effect of temperature on germination of three varieties of corn. It was used three different maize varieties: BRS Assum black, BRS011, and BRS033 Asa Branca. The treatments consisted of three controlled temperature: 20°C and 40°C and 30°C. The variables analyzed were percentage of germination; germination speed index; mean germination time; germination frequency; height change and stem; stem diameter; number of leaves; chlorophyll a, b, overall; fresh and dry stem, leaf and root. The Tukey test was applied at 5%, in the variables when significant. The 30°C temperature range is ideal for germination and early development of corn seedlings. The varieties studied do not differ significantly for dry mass production, except the roots, as well as the biometric variables. There are no differences between varieties in the production of chlorophyll. The temperature of 30 proved that influences the increased production of chlorophyll A and total; stem and leaves dry weight as well as the biometric variables. Keywords: Emergence, seedling, variables, production. R E S U M OAumentos na temperatura ambiente podem influenciar de forma significativa o processo de germinação de diversas espécies vegetais. Podem interferir diretamente em atividades fisiológicas, bioquímicas entre outras, alterando desta forma a máxima capacidade das sementes em ativar a emergência das plântulas, bem como a formação morfológica das plantas. O objetivo desse estudo foi simular em câmaras de crescimento o efeito de diferentes temperaturas na germinação de três cultivares de milho: BRS Assum preto, BRS011 e BRS033 Asa Branca. O experimento foi implantado a partir da utilização dos tratamentos formados por três temperaturas controladas: 20º, 30º e 40ºC. As variáveis analisadas foram percentuais de germinação; índice de velocidade de germinação; tempo médio de