Abstract: A multi-functional biaxial tensile testing machine, which can be applied for both immediate and creep biaxial tension tests on geosynthetics, is designed and developed to investigate the mechanical propertes of geosynthetics under biaxial tension states. In immediate tension test mode, electro motors are used to apply tension force or displacement loads with different proportions in the two perpendicular directions. In creep tension test mode, the tension loads are applied by a set of iron weight. And three groups of large deformation creep tests can be carried out simultaneously using the machine. Preliminary experimental results show that the new machine can be employed to conduct biaxial tension tests on geosynthetics under implicit stress and strain paths. The new machine provides a scientific and effective means for studying the mechanical properties of geosynthetics under biaxial tension states.