In view of the present parametric modeling method of parts based on UG secondary development, the paper presents two more simple and rapid modeling. The first one takes the parametric modeling of inner gear as an instance, by first establishing a template model part, then in its dialog callback function, code change parameters, last updated parameterized parts. The second one takes ultrasonic transformer as an example, using JA file recording function in UG modeling environment to record the modeling process. In the callback procedure of the dialog box, the recorded code is used to replace the part's modeling program code which originally developed by API or grip. It can realize parametric part after the input values of the dialog box are associated with the parameters of the model in the code. The application of the two methods can effectively reduce duplication designers to improve design efficiency.