Abstract: In this paper, the subtropical Northwest Pacific Ocean and its adjacent area are selected as the research region, and a large dataset is constructed to address the shortage of long-term time-series and high-resolution datasets of elevated ducts over the ocean. The mesoscale WRF model with a horizontal resolution of 12 km and a temporal resolution of 1 hour is used to conduct 11-year simulations over the study region from 2007 to 2017 through a continuous rolling method. The shipborne and island sounding data are utilized to evaluate the accuracy of model simulations. The decadal and seasonal distribution characteristics of elevated ducts occurrence probability, average height, and average strength are given, which provides data support for electromagnetic environment assessment, radar detection and communication guarantee over the ocean. The results indicate that the trends of temperature and humidity variation with height, as well as the phenomenon of elevated ducts, can be well reproduced by the WRF model. The subtropical Northwest Pacific and the northern South China Sea region are the sea areas where elevated duct occur frequently. The average occurrence probability over years exceeds 40%, the average height exceeds 500m, and the average intensity exceeds 7.5M-unit. However, the phenomenon of elevated duct rarely occurs north of 35°N in the simulated domain. The spatial and temporal distribution of elevated ducts shows significant seasonal differences. The occurrence probability, average height and average strength of the elevated duct are highest in winter, followed by spring and lowest in summer.