The present study will focus on superficial modification by alkalization of cellulose fibres obtained from Fique leaf as reinforcement in polymer matrices to produce a natural fiber composite that can be suitable for industrial purposes. Fique fiber is a hard vegetable fiber derived from a Colombian plant (Agave furcarea). An appropriate treatment, namely alkalization, of the fiber was chosen and carried out, but will be customized for this specific study to be more environmental-friendly and economical. A higher fiber-to-solution ratio as well as a low concentration would decrease the price of the treated fibers. The changes introduced to the surface morphology by the abovementioned treatment is then examined using a scanning electron microscope (SEM), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC) and FTIR analysis, and untreated and treated samples were.