Abstract: A model was established to analyze and predict effectively the wear life of rod. It is considered in this model: the two main reasons for partial-wear: borehole curving and rod blending under pressure in the down stroke. A calculating formula suggested by ΠΡΟΗΝΚΟΒ was used to evaluate the increase of abrasion thickness of rod with time, and the failure position and time were estimated in accordance with the increase of stress with the decrease of residual cross-section area at the point where the wear was worst. The comparison between the model result and the spot data was used to prove the reliability of this model. The principle that the revolving wellhead could retard the progress of wear was interpreted through the calculating result made by this model.