An experiment on mixed mineral grains of quarts, plagioclase and calcite dissolved in several aqueous organic acid solutions was carried out. The purpose of the paper was to compare the dissolving rate of the minerals in formation water containing abundant lowmolecular organic acids under reservoir condition and to probe the microcosmic mechanism of corrosion. The results indicated that all mineral grains were eroded more or less after the experiment; it exhibited that the weight of grain decreased, whereas the concentration of SiO2 and several metallic cations and pH in aqueous solution increased. Solubility of calcite was prior to that of silicate; the solubility of silicate increased obviously with the increase of experimental temperature whereas calcite remained. The fact that stability difference of different complexes formed by SiO2 and metallic cations results in the distinct difference of dissolving rates of minerals in different organic acids. Minerals were more easily dissolved in polyfunctional organic solution than in oxalic solution containing abundant Ca2＋. Precipitation of insoluble calcium oxalate on the surface of mineral grains worsens dissolution of calcite. Polycyclic chelates formed by polyfunctional organic acid and SiO2 have a high degree of stability in aqueous solution due to their substitution for oxygen atoms in the siliconoxygen tetrahedrons, and which would be conducive to the dissolving of alumino silicate and and migrating of silicon in solution