CNC technology based on STEPNC will be the future trend of CNC technology, and then the intelligent process planning based on machining parts is the key core for STEPNC oriented CNC. STEPNC oriented intelligent process planning system was studied, the framework based on STEPNC milling intelligent process planning system was constructed, and then the certain key technologies of the proposed system were investigated in detail. Based on SolidWorks development platform, the corresponding prototype system called as STICAPP was developed by VBNET. The specific application of the prototype system was specifically described by a typical part process planning. The result shows that the proposed system is valid and feasible.