The tropical surface wind speed in boreal winter reaches a maximum near Taiwan. This stable wind resource may be used for future development of clean energy. How this surface wind energy source changed in past 141 years is investigated using the 20th century reanalysis dataset and CMIP5 models. Our observational analysis shows that the surface wind speed experienced a weakening trend in the past 141 years (1871 – 2010). The average decreasing rate is around -1.4 ms-1 per century. The decrease is primarily attributed to the relatively cooling in sea surface temperature (SST) in subtropical North Pacific, which forces a large-scale low-level anti-cyclonic circulation anomaly in situ and thus is responsible for the occurrence of the southerly trend near Taiwan. The formation of the relative SST trend pattern is mainly attributed to the greenhouse gas effect associated with anthropogenic activities. The southerly trend near Taiwan is more pronounced in boreal winter than in summer. Such a seasonal difference is attributed to the reversed seasonal mean wind, which promotes a more efficient positive feedback in boreal winter.