Biofoam based on Poly ( Lactic acid) containing of wood Kraft lignin and polyethylene glycol (PEG) have been developed by high pressure foaming technique using compressed CO2 gas.Two binary systems based on PDLA/PEG and PDLA/lignin have been studied to understand the role of plasticizer (i.e., PEG) and filler (i.e., lignin) on the foaming behavior of PDLA. Both plasticized PLA and PLA biocomposites were prepared by melt mixing in twin-screw extrusion with various compositions of polyethylene glycol and lignin. The injection molded PLA samples were gas saturated with CO2 for 48 hrs and foamed in a glycerin bath at 160 oC and at 100 oC. Compared with unplasticized PLA samples, the plasticized PLAs shows significances enhancement in foamability. Influences of plasticizer content on cell expansion in foam morphology of plasticized PLA biofoams were studied. Lignin enhances the cell nucleation, during foaming process leads to microcellular biofoam composites. The closed cell microcellular morphology obtained from PDLA/ligin and macro-cellular cell morphology obtained from PDLA/PEG were examined using scanning electron microscopy and analyzed by ImageJ software. Different crystalline structure and degree of crystallinity induced by the biaxial stretching at different foaming temperature were studied by Wide angle X-ray diffraction (WAXD). Impact strength of plasticized PLA biofoam samples was found to be 3-4 times higher than unfoamed samples. Specific density of plasticized biofoam and bio-composite foam was determined and two to three times reduction in foam density was observed. Keyword: Bio-foam composites, cell nucleation, micro-cellular foam, high pressure foaming process.