OBJECTIVE： To study the effect of hydrophilic/hydrophobic nano-silica with different adding amount on the stability of lipo-emulsion. METHODS： Glycyrrhetinic acid lipo-emulsion 4 mL was taken， respectively adding into 0.5％， 1.0％， 1.5％ （m/m， the same below） hydrophilic nSiO2， and 0.4％， 0.75， 1.0％ hydrophobic nSiO2， incubating 2 h in 30 ℃ water； the same batch of Glycyrrhetinic acid lipo-emulsion was treated as blank control. The forms were observed under electron microscopy after treatment， absorbance value was determined， the stability parameter （KE） was calculated according to the absorbance value， then the adding amount of nSiO2 was optimized， 3 batches of preparations was prepared， and the verification test was conducted. RESULTS： The spherical structure was Glycyrrhetinic acid lipo-emulsion in the electron microscopy， the substance wrapping its surface white ring （fully wrapped） or semi-circular structure （not fully wrapped） was nSiO2. KE of hydrophilic nSiO2 were 4.66％， 5.01％ and －2.08％， and KE of hydrophobic nSiO2 were 3.02％， 4.51％ and 7.24％. The optimized adding amount of hydrophilic nSiO2 was 0.2％， 0.3％ and 0.4％， hydrophobic nSiO2 was 0.1％， 0.2％ and 0.3％； KE were 6.19％， 3.05％， 7.84％， 8.42％， 2.41％， 2.93％， respectively. The optimal adding amount was 0.3％ hydrophilic nSiO2 and 0.2％ hydrophobic nSiO2； the 3 batches of preparation showed the optimum stability in its own adding amount. CONCLUSIONS： Both hydrophilic and hydrophobic nSiO2 can improve the stability of Glycyrrhetinic acid lipo-emulsion， and preferably 0.3％， 0.2％.