The present invention refers to a process for obtaining thermoplastic composite pellets reinforced with cellulose pulp or additive cellulose pulp, cellulose fibers, and/or hydrophilic material from renewable source, and/or natural source material comprising the steps of cellulose pulp dry processing carried out in a binder mill, and/or plastic agglomerator and/or densifier, and preparation of the masterbach comprising the steps of drying the pulp and the thermoplastic materials, preparing the compositions of polymer and cellulose fiber, milling the masterbatch produced, drying the product, extruding the polymer and the masterbatch, and injecting the obtained material.