Abstract: Methyl-2-(4-hydroxyphenoxy) propionate is an important intermediate for the synthesis of aryloxyphenoxy propionate (APP), a high efficiency herbicides. There is a certain gap between the existing products and the ideal one, such as the particle size and the size distribution. Central composite design (CCD), a kind of responsive surface methodology, was used to explore the effects of stirring rate, cooling rate, seeding quantity and aging time on the particle size and the coefficient of variation (C.V.) of methyl-2-(4-hydroxyphenoxy) propionate. On the basis of regression analysis, regression equations related to responsive values and factors were developed, respectively. For control of crystal size, the most important parameters were aging time, seeding quantity, stirring rate and cooling rate, respectively. For control of crystal size distribution, the most important parameters were stirring rate, seeding quantity, aging time and cooling rate, respectively. The interactions between stirring rate and seeding quantity, stirring rate and aging time, were important as well. The crystallization process was optimized using the following parameters: Stirring rate of 400 r/min, cooling rate of 5 °C/h, seeding quantity of 2.5 g, and aging time of 20 min. In the above conditions, methyl-2-(4-hydroxyphenoxy) propionate were prepared, with a purity of above 98%, an average particle size of 1 054.27 μm in narrow size distribution, and 0.891 3 in C.V. The predicted values well fit the experimental values, which thereby demonstrates that the established models were accurate and reliable for the analysis and prediction of the reactive crystallization process.