The 14-day medium-range precipitation forecast is important for drought and flood forecasting and water resources scheduling management. TIGGE (THORPEX Interactive Grand Global Ensemble) provides basic data for regional medium-range ensemble precipitation prediction. Based on the ensemble forecasts of CMA, CMC, ECMWF, JMA and NCEP in the TIGGE datasets in Jiangsu Province, we evaluated their medium-range precipitation forecast results. We mainly used such evaluation methods as the TS, BS, mean absolute deviation, and mean square root error. The results showed that the forecast scores of light and moderate rain during the entire forecast period were all relatively high. The light rain had the highest TS (mostly around 0.5) statistically. However, there were obvious missing reports of precipitations above the moderate level. For the 15-day forecast of daily cumulative rainfall, there was only a 3-day decay period, after which all the error indicators remained stable. The prediction bias in a lead time of over 3 days was mainly overprediction. Meanwhile, the cumulative rainfall forecast of over 5 days was significantly larger than the actual value. The forecast effect was the best in winter and the worst in summer, and the effect in northern Jiangsu was better than that in southern Jiangsu. Across the five representative modes, the ECMWF and JMA modes respectively showed the best performance in rainfall categorical forecast and daily cumulative rainfall forecast.