Rice husk is an agricultural waste that potentially produces high-purity amorphous silica as the source of the precursor of mesoporous silica MCM-41. To obtain pure silica, acid leaching was applied to the rice husk followed by heating treatment in the furnace and synthesized by a sol-gel technique to produce amorphous silica. In this research, mesoporous silica MCM-41 were synthesized by a sol-gel technique assisted by CTAB as a template, then titrated with acetic acid and hydrothermal in the teflon line-autoclave. Various CTAB concentrations were applied as the research variable parameters. X-ray diffraction pattern shows that silica has an amorphous-like curve. FTIR data showed the presence of Si-O-Si function groups in the sample. SEM results showed coral reefs-microstructure with the particle sizes about 243-482 nm. TEM image showed the porous structure on the silica surface and formed a hexagonal structure mcm-41. The diameter of the shaft was 3.13-3.58 nm, hence the resulted silica material is classified as mesoporous material.