The present invention relates to a method for preparing a biodegradable scaffold and the biodegradable scaffold produced thereby comprising: preparing Poly D-L lactic acid (PDLLA) microparticles and macroparticles entrapping water soluble drugs with high efficiency and fabricating biodegradable drug delivery scaffold by methanol treatment of microparticles and macroparticles prepared in preceding step and wherein, macroparticles and microparticles are formed using cetyl trimethly amminium bromide (CTAB) in the external aqueous phase and pH is maintained at a value of 6.