We determined periods and orbital parameters for two binary systems with O-type components, namely Tr 16 Nº1 and HD 64315. Tr 16 Nº1 has a period p=1.5 days, components O9+O9 and minimum masses M₁ sen³i=17 M⊙ and M₂ sen³i=19 M⊙. HD 64315 has a period p=1.34 days, components O6+O6 and minimum masses M₁ sen³i=3.8 M⊙ and M₂ sen³i=3.3 M⊙.Asociación Argentina de Astronomí
