In this study, we attempt to investigate the effect of silica size on the thermal, mechanical and biodegradable properties of polylactide/amino-silica (PLA/SiO2) composite material, by preparing the PLA/ SiO2 hybrids containing different size of silica particle through twin-screw extruder. First of all, we prepared amino-functionalized silica particles through performing the conventional base-catalyzed sol-gel reaction of methyltrimethoxysilane (MTMS) and 3-aminopropyltrimethoxysilane (APTMS). The average diameter of silica particle employed in hybrids was 150 nm (S-silica) and 1μm (B-silica), respectively. Systematically comparative studies on the thermal properties and mechanical strength of hybrids containing two different sizes of SiO2 particles materials were carried out on a basis of studies of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). It should be noted that the mechanical strength of hybrids containing smaller size of silica particles was found to reveal significant improvement in storage modulus as compared to its corresponding counterpart based on the DMA investigation. Moreover, the thermal stability of hybrids containing smaller size of silica particles was found to reveal slight improvement in glass transition temperature as compared to its corresponding counterpart based on the DSC investigation. Eventually, the as-prepared hybrids were found to exhibit almost similar degradation behavior to that of neat PLA.