Cellulose is one of the most abundant natural resource and can be used as biodegradable composite matrix material in many applications. Phase change materials (PCMs) are thermal energy storage (TES) materials and can reduce energy consumption of heating and cooling applications. This study aims to prepare cellulose-based composites containing myristic acid (MA) as PCM and methyl cellulose and hydroxyethyl cellulose as composite matrix using direct impregnation method without any pre-treatment or modification step. The primary aim in PCM composite production is to realize the phase change in the composite matrix by trapping the matter in the composite. The properties of composite material were determined with scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. The maximum latent heat was measured 71.3 J/g for MA/methyl cellulose composites and 32.7 J/g for MA/hydroxyethyl cellulose composites. We recommended that the prepared leakage free cellulose-based composites can be used as biodegradable energy storage materials with good reliability and thermal properties for thermal energy storage applications.