Graphitic carbon nitride (g-C3N4), a polymeric semiconductor that finds potential applications in multiple areas, is shown to feature amphiphilic behavior. Since the feasibility of g-C3N4 aqueous colloids is well-established, g-C3N4 can be viewed as an effective and well-accessible colloidal amphiphile. Its activity at different interfaces (liquid-liquid, liquid-solid, and liquid-air) is illustrated: g-C3N4 is able to stabilize Pickering emulsions formed by water and organic solvents, and also, gas-filled g-C3N4 frameworks based on those emulsions are obtained by natural drying. Hydrophobic solid substances like graphite and carbon nanotubes are smoothly dispersed in water assisted by g-C3N4. Besides, networklike g-C3N4 membranes floating on a water surface are created and can be readily transferred to substrates. These findings provide many opportunities for the processing of g-C3N4-containing functional materials and devices.