In this study, the effects of degradation on ascorbic acid (AA) in asparagus-lemon juice with different blending ratios were investigated during storage. The R 2 values of the first-order kinetic model for predicting AA loss were 0.8216-0.9990, indicating that the model described well the degradation of AA in asparagus-lemon juice with different blending ratios. Response surface methodology (RSM) was applied to optimize the blending ratio of asparagus-lemon juice during storage. The optimum blending ratios that selected by the RSM were: 23%, 26%, 27%, 28% and 29% of diluted asparagus juice blended with 85% of diluted lemon juice, and the desirability were 0.820. The RSM correlation coefficients (R 2 ) between experimental and model predicted values ranged from 0.6394 to 0.9975. Therefore, RSM and the first-order model may be effective tools to optimize the blending ratio of blended juice and AA degradation in juices.