Abstract: In recent years, amino acid-based amphoteric collectors have achieved good separation effects in the process of phosphate ore beneficiation. In this study, sodium N-dodecyl-β-aminopropionic acid (C12Giy) was prepared by methyl acrylate method, and the regression model and response surface curve analysis were used to optimize the synthesis conditions. The results show that the influence of reaction temperature on the recovery of flotation phosphate concentrate is the most obvious, and the influence of reaction time on the grade of phosphate concentrate is the most obvious. The interaction between reaction time and reaction temperature has the most obvious influence on the recovery and grade of phosphate concentrate. Through the analysis of Design Expert software, the optimal synthesis conditions of amphoteric collector C12Giy are as follows: the molar ratio of dodecylamine and methyl acrylate is 1 : 1.5, the reaction time is 40 min and the reaction temperature is 70 ℃. When C12Giy synthesized under this condition was used as flotation collector, the grade and recovery of phosphate concentrate were 28.78 % and 64.04 %, respectively. The theoretical comprehensive efficiency value and the actual comprehensive efficiency value were 5.74 % and 5.49 %, respectively, indicating that the prediction results of the model were reliable.