It is critical to the success of enterprise systems (ES) assimilation that employees acquire sufficient knowledge and apply the knowledge effectively in routine system use. Drawing from knowledge management and socialization theories, we develop a theoretical model for better understanding how management could exercise socialization tactics to promote the transfer of knowledge, and thus improve the knowledge application outcomes in ES assimilation. We validate the model through survey data from employees in 14 companies which have implemented ES for more than one year in China. We find that socialization tactics strongly impact the properties of knowledge acquisition (depth, breadth, and linkage), which in turn influences knowledge application by users (habitual and extended use). Interesting, while the depth of knowledge impacts the breadth and linkage of knowledge, it does not have a significant direct impact on knowledge application. Theoretical and practical implications of these findings are discussed.