This study had as objective to evaluate transpiration and stomatal conductance of two commercial clones of Eucalyptus sp in periods between February and June of 2010. Leaf scale was associated with global radiation (RG) and different levels of water availability. Data on transpiration (E) and stomatal conductance (GS) of the clones were obtained by porometry and were associated with global radiation. The clones were under the same range of predawn leaf water potential (0 to -3,0 MPa). The results showed significant differences between clones, and the C041 clone had greater control of transpiration. The P4295 clone had a higher decrease of the relation transpiration and stomatal conductance per radiation unity, and the values were consistently higher than those of the C041 clone. However, statistically significant differences were found in the relation Etotal/Rgtotal only for predawn water potentials < -1.0 MPa. 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