A novel porous Yb4Si2O7N2 material with uniform open-cell network structure was fabricated from the reaction between SO4, Yb2O3, and SiO2. The formation of Yb4Si2O7N2 during heating was studied using X-ray diffractometry. The porous structure was characterized using scanning electron microscopy and mercury porosimeter. It is shown that the formation of Yb4Si2O7N2 phase starts at ∼ 1150° C and completes at 1350° C for 4 h, accompanied by the development of open-cell network structure. The necks between Yb4Si2O7N2 particles become much thicker with increasing temperature because of the coarsening of Yb4Si2O7N2 particles, thus leading to a uniform three-dimensional network structure. Furthermore, the pore size can be well controlled by adjusting reacting temperature and altering atmosphere.