A new method of using a circular water surface sampler was developed to evaluate the dry deposition fluxes and deposition velocity (=deposition flux/atmospheric concentration) of particulate mercury, Hg(p) and gaseous divalent mercury, Hg(II) individually. Observations were conducted at a study site located in the Tokyo metropolitan area. The results showed that the water surface sampler could be used to measure the dry deposition fluxes of mercury and other trace metals (Cd, Cu, Mn, Pb and Zn). The dry deposition velocity for trace metals other than mercury, which exist entirely in particulate form, increased linearly with increasing median diameter in the size distribution. Using this regression equation, the dry deposition velocity for Hg(p) can be estimated from its median diameter, which allows to calculate the dry deposition flux for Hg(p). On the other hand, the dry deposition flux for Hg(II) can be obtained from the difference between the deposition flux measured using the water surface sampler and the estimated deposition flux for Hg(p). This makes it possible to estimate the dry deposition velocity for Hg(II) by dividing the deposition flux by the atmospheric concentration.