It is estimated that 60% of the area of cultivated pasture, in the Brazilian Savannah, is degraded or in process of degradation, due to, among other causes, the lack of nitrogen. The Stylosanthes genus is the legume which has the greater number of cultivars used in tropical pastures, however, its seeds have characteristics which can difficult the formation of an adequate stand of plants on pasture. In this research the aim was to evaluate the effects of priming in the speed and uniformity of the Stylosanthes capitata, S. macrocephala and S. guianensis seeds germination. The seeds were kept for 12, 24, 36 and 48 hours in aired media PEG 6,000 at 0.0, -0.5, -1.0 and -1.5MPa. Afterwards, they were sent to the germination test. The variables analyzed were germination percent, germination speed index (GSI) and average germination time (AGT). For S. capitata it is recommended priming at 0.0 MPa for 10 hours, and for S. macrocephala the recommended potential is -0.5 MPa. However, for the S. guianensis the priming is not recommended under the time and potentials evaluated in this research.