Abstract: OBJECTIVE To optimize the preparation process of Kunyining granule. METHODS With the paste-forming rate and total content of paeoniflorin as the indexes, the optimal water-extraction condition was screened by orthogonal design. With hydroscopicity, fluidity and formability as the indexes, the appropriate ratio of the excipient and the formula were selected. RESULTS The optimum water-extraction condition was as follows: 10-fold water, decoction for 2 times and 1.5 hour for each time. The optimal ratio of the excipient and the formula for preparation of Kunyining granules were one proportions of the extract and one proportion of the excipient which consisted of lactose, sucrose powder and dextrin(3∶1∶1). CONCLUSION The technology is effective, scientific, reasonable, and practical.