Porous structure has wide application in industry due to some of its unique properties such as low density, low thermal conductivity, high surface area, and efficient stress transmission. Both templating and foaming agent methods have been used to fabricate porous structures. However, these methods can only fabricate simple geometries. In recent years, many studies have been done to use additive manufacturing (AM), e.g., stereolithography apparatus (SLA), in the fabrication of porous structure; however, the porosity that can be achieved is relatively small due to the limited accuracy in building microscale features on a large area. This paper presents a projection-based SLA process to fabricate porous polymer structures using sugar particles as the foaming agent. With a solid loading of 50 wt.% of sugar in photocurable resin, the method can achieve a structure with much higher porosity. As shown in our results, the method can increase the porosity of fabricated scaffold structures by two times when compared to the current SLA method.