The present invention relates to an injectable composition for skin tissue regeneration or skin tissue volume increase comprising hollow porous microspheres comprising a cavity in the center thereof and a barrier surrounding the cavity and comprising fine pores. The hollow porous microspheres comprised in the composition according to the present invention have a small particle size, thus can be administered by an injection into skin tissue, and allow moving skin tissue cells to effectively proliferate within the cavities. After a predetermined period elapses, the newly proliferated skin tissue cells maintain the volume thereof even after the hollow porous microspheres biodegrade inside skin； thus, skin tissue regenerative effects can be safely maintained for a long time.
