Abstract:The characteristics of tropical cyclones (TCs) on Western North Pacific in 2017 were analyzed by using the best-track data, CMA operational forecast data, ECMWF products and NCEP SST_RTG data. Results can be summarized in the following three perspectives. The first is the tropical cyclogenesis. TCs have obvious characteristics of the cluster of tropical cyclogenesis. The generating locations are inclined to be westward. There are more TCs that generated on South China Sea than those in other areas. The second is TCs’ activities. It can be concluded that the annual activity level is low, TCs’ extreme intensity is rather weak, and the number of super typhoon is anomaly small. The third is TCs’ landing. More TCs made landfall this year, and the landing locations are inclined to be southward and the average intensity of landing TCs is weak in general. Estimations of track errors in this year show that there are small increases compared to those of 2016, with the value of 74, 137, 233, 318 and 428 km for 24, 48, 72, 96 and 120 h lead time, respectively. As for track forecast skill, CMA is ahead of JMA and JTWC except the 120 h lead time. The intensity errors are 3.6, 5.4, 6.6, 7.4 and 6.8 m·s-1 for 24, 48, 72, 96 and 120 h lead time, respectively, decreasing a little compared to the errors in 2016. It is noteworthy that the error of 24 h lead time is the lowest in records. The intensity forecast skill is between JMA and JTWC. The forecast difficulties are the complicated interaction between binary or among multiple TCs and the intensity forecast of RI TCs off-shore.