Creating lightweight materials with desired mechanical properties has long been an engineering pursuit, and the rise of three-dimensional (3D) printing techniques has made the fabrication of lightweight, porous materials with tailored architectures not only possible but also feasible. A variety of cellular materials based on plastics, metals and ceramics with engineered mechanical responses were created 1-3, but 3D printing of cellular rubbers is still a challenge. Here, a 3D direct ink writing technique was adopted to print a viscoelastic silicon rubber/nano silica system into orderly arranged sub-millimeter struts. By controlling the size, content and interface of nano silica, the particle-particle interaction and particle-polymer interaction could be varied, so the rheological behaviour of silicon rubber/nano silica composite could be tailored, and a viscoelastic system with a solid-like rheological behaviour (G’ >G”) at low oscillation stress and a liquid-like rheological behaviour (G” >G’) at high oscillation stress could be obtained. In this way, the system is printable and 3D-printed silicon cellular architectures could be prepared after thermal curing. By manipulating the specially designed architectures of the printed 3D patterns, materials with unique stress-strain behaviour could be obtained. Besides, the printed solids show lower compressive set compared to tradition silicon rubber foams with the same density, which is beneficial to their long-term services. This work not only paves a feasible way to control the cellular structure of elastomers in the sub-millimeter scale, but also suggests the ability to tailor mechanical properties of cellular materials via micro-patterned design, which may find potential applications in emerging fields or replacement of traditional foams.