In the overall evaluation of data acquisition system(DAS),it is the most important aim to identify and evaluate the dynamic characteristics of DAS.Through selecting several relatively independent indexes,the dynamic characteristics of DAS has been presented overall in this paper.And then the dynamic characteristics given by methods of dynamic effective bits,transfer function,step response,and amplitude frequency and phase frequency characteristics respectively have been proposed by several special modelling methods.As a result,the overall evaluation of the dynamic characteristics of DAS has been solved.