A new hypoplastic constitutive model with a modular structure is presented for granular soils. The modular structure allows the application of the constitutive model with very little material information under restriction of the soil effects to be reproduced. The more material information available, the better the stress-strain behavior of the material can be represented. The basic model and six modules are presented that allow to model soil phenomena like barotropy, pyknotropy, load history and small strain stiffness. Laboratory tests are simulated to show the performance of the constitutive model.