Objective:To optimize formulations of total flavonoids from Euphorbia humifusa（EFCTT） by central composite design-response surface method.Method: With the amount of lactose and L-HPC

coating weight gain as factors

with cumulative release at 2

6

9 h of quercetin from total flavonoids as index

Design-Expert software was used to fit multivariate linear models and quadratic multinomial models for experimental data

and obtained optimum mathematical model

drew effect diagram and contour maps

optimum prescription was obtained by overlapping contour maps and verified.Result: The correlation coefficient of quadratic multinomial models was better than multivariate linear models

and it was the final fitting model;Cumulative release in four time point of optimum prescription was close between observed value and predicted value with relative deviation was less than 5%.Conclusion: Model established by central composite design-response surface method had good predictive

it could be used to optimize prescription of EFCTT.