The poly methyl acrylic acid(PMAA)was grafted on the surface of micron-sized silica gel with the method of “graft from” to prepare grafted particles PMAA/SiO2.The chemical structure of the grafted particle was characterized by means of infrared spectroscopy(FTIR)and the grafted particle was observed by metalloscope photograph.The adsorption of arginine on the grafted particles PMAA/SiO2 was studied with batch method.The effects of the main factors such as pH value of the medium,ion strength and temperature on the adsorption property of PMAA/SiO2 were investigated.The experimental results showed that the functional composite-type particles PMAA/SiO2 exhibit strong adsorption ability for the alkaline amino acids,whereas the adsorption ability for the acidic amino acids is weak.The adsorption capacity of PMAA/SiO2 for arginine has a maximum value at pH=7,which is 239 mg·g-1.The adsorption capacity decreases with the increase of temperature and salinity.