The daily precipitation of 652 rain gauges over the Huaihe River Basin and the daily precipitation forecasting products of ensemble system of China Meteorological Administration from TIGGE (THORPEX Interactive Grand Global Ensemble) archive are employed to construct new observation data processing methods. The methods are based on taking observation uncertainties into consideration when processing observational data to assess ensemble precipitation forecasts. The observation probability (OP) method and observation percentile (OPC) method are presented in the paper, which are compared with traditional method of dealing with observation when accessing ensemble precipitation prediction skill, reliability and resolution for different precipitation thresholds. The Brier Score and Brier Skill Score of three methods are calculated. The results show that the Brier Scores are degraded and this degradation means the Ensemble Prediction System (EPS) is better to use OP method and OPC method for all of the thresholds, especially for middle and lower precipitation thresholds. The results of Brier Skill Score indicate that, the prediction has forecast skill for 0.1, 5, 10, 15 and 25 mm·(24 h)-1 thresholds, respectively. New observation processing methods generally improve the resolution component of the Brier Skill Score, but a little bit degrade the reliability component of the Brier Skill Score.