In this study, an analytical realization of end-milling system was introduced using recursive parametric modeling analysis. Also, the numerical mode analysis of end-milling system with different conditions was performed systematically. In this regard, a recursive least square (RLS) modeling algorithm and the natural mode for real part and imaginary one were discussed. This recursive approach (recursive least square method : RLSM) can be adopted for the on-line system identification and monitoring of an end-milling for this purpose. After experimental practice of the end-milling, the end-milling force was obtained and it was used for the calculation of FRF (Frequency response function) and mode analysis. Also the FRF was analyzed for the prediction of an end-milling system.