Abstract: OBJECTIVE To optimize the extraction technology for total alkaloids from Solanum nigrum L. by Box-Behnken design. METHODS Based on the results of single-factor experiment, Box-Behnken experimental design combined with response surface methodology(RSM) was employed, with the ethanol concentration(A), solid-liquid ratio(B), extraction time(C) and extraction times(D) as the independent variables. The response variable was the amount of total alkaloids. Acid dye colorimetry and UV spectrophotometer were used to detect the content of total alkaloid in Solanum nigrum L. RESULTS The optimization processing parameters was as follows: A, B, C and D levels of 63.72%, 41.23 times, 54.93 min and extract twice, respectively. The content of total alkaloid was 1.40 mg·g^-1. CONCLUSION Box-Behnken experimental design is feasible, and highly predictive.