Abstract: To obtain the mechanical properties of a lattice material with large specific stiffness and specific strength, interlocked method was introduced to design and manufacture mixed triangular lattice grids. The effective stiffness of the stretching dominated lattice structures were analyzed by continuum method combined with finite element method. The compression and three-point-bending properties of the grids were achieved by experiments. The predicted stiffness was very close to the tested values and the validity of the continuum method was proved. The superiority of the grids in mechanical behaviors was illustrated by the tests.