Abstract: The present invention relates to a method of preparing green form polystyrene resin. More specifically, recyclable expandable material from general waste is made use of along with virgin expandable material and virgin hardening polymer for preparing green form polystyrene resin. Further, extruding the mixture yields green form compounded polystyrene resin with high melt flow index or gas injection into the green form compounded polystyrene resin results in synthesis of green form expandable capsules or beads thereof with desired properties. The present invention further facilitates the production of polystyrene molded foam used for insulation by puffing expandable green form capsules with pre-expander.