Abstract: Development of new synthetic strategies via organic photocatalysis in our group was described. Both photoacidic activity and photoredox activity of organic photocatalysts were discussed. A series of phenol-conjugated acridinium-based organic photoacids were rationally designed, synthesized and studied alongside commercially available phenolic catalyst, eosin Y. In the presence these photoacid catalysts and light, synthetic glycals underwent activation and coupled with a range of alcohols to afford 2-deoxy-glycosides in good yields with excellent a-selectivity. Moreover, a recent development of photo Lewis acid catalyst was described. In addition, a photocatalytic N-radical cascade reactions were discussed, including synthesis of pyrroloindolines, rapid synthesis of flustramide B, and remote allylation of uncativated sp3 C-H bonds.