This pioneering study explored the spatiotemporal variation, gas-solid partition, and potential sources of atmospheric speciated mercury surrounding the Taiwan Strait. Total gaseous mercury (TGM) and particle bound mercury (Hg_p) were sampled simultaneously at six coastal and island sites located on both sides and in the middle of the Taiwan Strait. Field measurement results showed that the campaign average concentrations of TGM and Hg_p at all sites were 4.56 ± 0.35 and 0.17 ± 0.02 ng/m³, with the range of 3.22–5.84 and 0.06–0.25 ng/m³, indicating that TGM and Hg_p partitioned as 96.09–97.02% and 2.98–3.91%, respectively, The spatial distribution results showed that the highest and lowest TGM and Hg_p concentrations were mostly observed at Xiang-An site in the suburban of Xiamen City and at Sandiaojiao site in the remote coast of New Taipei City, respectively. The seasonal variation of TGM at six sampling sites was in the order as: spring > winter > fall > summer, while that of Hg_p was in the order as: winter > spring > fall > summer. Regarding the levels of TGM and Hg_p, they increased gradually and consistantly from late fall to early spring when polluted air masses were transported from the Northeast Asia to the Taiwan Strait by Asian Northeastern Monsoons (ANEMs). On the contrary, the lowest concentrations of TGM and Hg_p were observed commonly in summer as clean marine air masses transported from the seas toward the Taiwan Strait. It was inferred that atmospheric speciated mercury surrounding the Taiwan Strait was mainly attributed from both local sources and long-range trasport (LRT) from the Northeast Asia.