Nanofibrilliated Cellulose (NFC) have attracted interest in the field of biopolymeric foam because of its abundant availability, biocompatibility, high tensile modulus and high surface area for water absorption. With these advantages, cellulose based foams can be replacement of synthetic foams in future and therefore gain huge scope in biomedical, packaging and water purification fields. Foam prepared from nanocellulose exhibits higher stability and absoprtion in compare to microcellulose based foam. Our aim of this work was to prepare surface modified nanocellulose based biofoam using wood pulp as precursor. In the first step, NFC was extracted from wood pulp by mechanical grinding method using super mass collider. The diameter of fabricated NFC was found to be in the range of 20- 50 nm as observed by TEM. Then the extracted NFC was surface modified using carboxylic acid to achieve better dispersion in water. Successful modification was characterized by FT-IR. By conductometric titration degree of substitution was found in the range of 0.3- 0.4. By using modified NFC dry foam structure was prepared by pickering emulsion using octylamine as stabilizer followed by freeze drying.Effect of NFC and Octylamine concentration on the foam stability was studied to achieve the optimum composition. Foam structure was characterized by morphological analysis, density measurement, foam stability (volume basis) and water absorbency. It was found with increasing concentration of modified NFC, stability of foam and water absorbancy increased compared to microcellulose foam.