Microphysical characteristics of fogs have been measured by the ground-based Forward Scattering Spectrometer Probes (FSSP) at the mountainous site (called Daegwallyeong) in Korea. The site is located 842 m above sea level. The mountain range falls steeply into the sea to the east of the site, but there are more gentle slopes to the other direction. This physical feature of the site leads to distinct differences in the fog characteristics between the east and west. The aim of this study is to investigate the influence of the wind direction and topography on the size and the number of fog droplets. Also this focuses on the climatological characteristics of fog droplets obtained during the long period. The measurements had been conducted from November 2003 to August 2010 except for the occasional fog in winter. Observational fog cases are classified into two groups according to the wind direction, the easterly maritime fogs and westerly continental fogs. The easterly fogs are subdivided into two groups with the orographic lifting; the orographic fogs and non-orographic fogs. The subdivision analysis gives a conclusion that the cloud condensation nuclei (CCN) type has more decisive effect on the fog droplet spectra than that of the orographic lifting. Easterly fog having the larger droplet size and number must be affected by the orographic lifting and the maritime nuclei. Size spectra of the easterly orgraphic fogs are broaden than those of the others. It seems that the orographic lifting due to the terrain is an effective factor in increasing the number of fog droplets and maritime nuclei is effective in broadening the size distribution.