Strontium (Sr) containing rare-earth oxysilicate apatite A(4)(I)A(6)(II)(SiO4)(6)O-2 is considered a good matrix to accommodate radionuclide as its cation sites can incorporate lanthanide elements other than Sr. Here, we report a study on the synthesis of Nd8Sr2(SiO4)(6)O-2 and Yb8Sr2(SiO4)(6)O-2, which adopt P6(3)/m apatite symmetry, as well as the characterization of crystallographic structures using X-ray diffraction and electron microscopy. It is found that A(I) position is shared by Nd, Yb and Sr, and A(I)O(6) polyhedra are face-connected, forming column structures, which are linked to SiO4 tetrahedra, creating continuous channels. The Rietveld refinement shows that Nd and Yb prefer the A(II) position in the channel. The twisted angle of adjacent triangle faces in an A(I)-O polyhedron along [001] is a critical parameter to identify the channel volume and its value varies when different cations are incorporated. The twisted angles for Nd-apatite and Yb are 24.2 degrees and 22.7 degrees The findings provide a new insight into nuclear waste stabilization by apatite-type structure.