Phyllanthus urinaria L. (P. urinaria) is one kind of traditional Chinese medicine with many bioactivities. Corilagin and geraniin are the major compounds with bioactivities in P. urinaria. Response surface methodology(RSM) was used to optimize the best conditions during the extraction process of corilagin and geraniin. By single-factor experiments, four variables of extraction were investigated. Then a Box-Behnken central composite design consisting of 29 experimental runs and 5 replicates, at the zero point was applied, and a regression model was used to predict the optimal extraction yield. The optimal conditions were as follows: ethanol concentration 65.38%, liquid/solid ratio 20.14:1, extraction temperature 81.55 degrees C, and time 2.46 h. Under the optimal conditions, the experimental value was consistent with the predicted response value, which indicates that response surface methodology is a feasible method that was validated for optimization of the extraction of corilagin and geraniol from P. urinaria.